Best Drain Cleaner For Black Sludge

We’ve all had to deal with it before – the drain is blocked by that horrible black sludge.

If you don’t keep on top of cleaning your drain, the accumulation of waste substances, everything from toothpaste to hair and food waste, eventually becomes the dreaded black sludge.

When you come to face the black sludge blocking your drain, you’ll need to arm yourself with a drain cleaner capable of doing the job.

That’s why we’ve put together this guide – to help you find the best drain cleaner around for getting rid of your sludgy nemesis. 

Without any further ado, let’s get started. First, an overview of our top drain cleaners for removing black sludge. 

Our Top Drain Cleaners For Black Sludge

  1. Green Gobbler Enzyme Drain Cleaner– A powerful drain cleaner that uses enzymes to break down the organic waste that makes up black sludge.
  2. Drano Max Gel Drain Clog Remover and Cleaner– A powerful, cost-effective chemical formula that can unblock drains in as little as 15 minutes.
  3. Bio-Clean Drain and Septic Cleaner– Biodegradable formula contains billions of enzymes that digest and break down organic waste within days.
  4. RID-X Septic Treatment– Designed to be flushed down the toilet, voted the number one brand with septic professionals. 
  5. Thrift T-100 4-in-1 Granular Drain Cleaner– Odorless alkaline powder that when mixed with hot water can clear a pipe in under a minute. 
  6. Rejuvenate Drain Pipe and Garbage Disposal Cleaner/Deodorizer– Handy drain cleaning pods perfect for your kitchen sink.

Drain Cleaner Reviews

Green Gobbler Enzyme Drain Cleaner

Green Gobbler ENZYMES for Grease Trap & Sewer - Controls Foul Odors & Breaks down Grease, Paper, Fat...

This drain cleaner from Green Gobbler is an absolute godsend when it comes to unblocking drains clogged by black sludge.

That sludge is usually an agglomeration of organic matter, including things like oils, fats, grease, starch, and proteins. That’s why the Green Gobbler Enzyme Drain Cleaner is so effective against it.

This drain cleaner has been specially formulated with enzymes that target and break down this organic matter, meaning your drain will be free of black sludge and completely unblocked in next to no time.

It eliminates any foul odors you might be experiencing, too. 

The added bonus is that regular use of this drain cleaner will help to keep your entire plumbing system healthy, all the way from the plug hole in your sink, right through the pipes, and even down into your septic tank, should you have one.

That’s because of the bacterial formulation of this drain cleaner. Over time, the bacteria in the drain cleaner will establish colonies and begin to spread right throughout your drain lines and pipes.

Don’t worry, though! This is a good thing, as the bacteria will help to prevent any significant sludge build-up and associated blockages.

Oh, and did we mention that it can reduce your bills by reducing the frequency of costly septic tank pump-outs? 

As if all that wasn’t enough, using a bacteria-based formula such as this one is a much safer alternative than using chemicals like sodium hydroxide, which, while effective, aren’t particularly kind on your pipes.

All in all, this is an excellent drain cleaner for getting rid of black sludge. In fact, Green Gobbler is so confident that you’ll be satisfied with your purchase that they offer a 30-day money-back guarantee. 


  • Non-corrosive bacterial formula.
  • Eliminates foul odors.
  • Functions as an effective preventative with regular use. 


  • Comparatively costly. 
Green Gobbler ENZYMES for Grease Trap & Sewer - Controls Foul Odors & Breaks down Grease, Paper, Fat...
  • Green Gobbler ENZYMES for Grease Trap & Sewer - Controls Foul Odors & Breaks down Grease, Paper, Fat...
  • Green Gobbler ENZYMES for Grease Trap & Sewer - Controls Foul Odors & Breaks down Grease, Paper, Fat...
  • TARGETS FOG, EVEN AS pH DECREASES. Green Gobbler Enzyme Drain Cleaner aids in the biological...
  • ULTRA-FAST ODOR ELIMINATION. Green Gobbler Enzyme Drain Cleaner eliminates odors associated with...

Drano Max Gel Drain Clog Remover and Cleaner

Drano Max Gel Drain Clog Remover and Cleaner for Shower or Sink Drains, Unclogs and Removes Hair,...

This chemical drain cleaner sits at the other end of the price spectrum from Green Gobbler, but don’t let that fool you into thinking this isn’t an effective drain cleaner. It most certainly is.

So why is it so popular?

Well, it’s easy to use and effective. It cuts right through any standing water that your blockage may have caused and gets right to the heart of the problem, where its specially designed fast-acting formula gets to work on the blockage.

It doesn’t just work on minor blockages, like hair clogs, either. It’ll have that black sludge gone in mere minutes!

All you have to do is tip one-fifth of a bottle down your drain and wait for 15 minutes, then flush with some hot water.

With any luck, your blockage should be a problem no more. One top tip that we’ve picked up from reviewers is to make sure you use boiling water rather than simply hot water for the most effective results.  

It’s worth remembering that although this product is safe for use on PVC, metal pipes, septic systems, and garbage disposals, it does contain caustic chemicals like sodium hydroxide and sodium hypochlorite.

This means you’ll have to exercise caution when using Drano Max Gel, being careful not to get it on your skin or in your eyes. And, of course, you’ll have to keep it out of reach of children and pets. 

Overall, Drano Max Gel is another great way to get rid of the black sludge blocking your drain. If it doesn’t? No problem! Like Green Gobbler, Drano offer a money back guarantee.


  • Unblocks drains in 15 minutes. 
  • Money back guarantee.
  • Good value for money. 


  • Contains dangerous caustic chemicals.
Drano Max Gel Drain Clog Remover and Cleaner for Shower or Sink Drains, Unclogs and Removes Hair,...
  • TRUSTED BRAND: Drano Max Gel Drain Clog Remover is the #1 Selling Gel Drain Cleaner*. Avoid spending...
  • FAST-ACTING: Starts working in 7 minutes. For best results, pour 16 oz slowly over drain. For...
  • REMOVES CLOGS: Pours through standing water straight to the clog. Use Drano whenever major clogs...
  • SAFE ON PIPES: Safe for bathroom and kitchen and. Drano Max Gel includes an ingredient to protect...

Bio-Clean Drain and Septic Cleaner

Bio-Clean Drain Septic 2# Can Cleans Drains- Septic Tanks - Grease Traps All Natural and 100%...

This is another drain cleaner that, as the name suggests, takes the organic approach to cleaning. Its formula contains no toxic chemicals that could damage your pipes or have negative health impacts on your family.

Instead, the formula is entirely composed of a special combination of natural microbes and enzymes that removes the dead organic matter making up black sludge by digesting it. 

As we saw with Green Gobbler, using an organic formula doesn’t have to be any less effective than using a heavy-duty chemical drain cleaner, and that is very much the case with Bio-Clean.

It does an incredibly thorough job of cleaning out even the most clogged drains, saving you the time and effort of fetching the drain snake or even the plumber.

It must be said, however, that this isn’t an instant fix for drains blocked by black sludge.

When you first buy Bio-Clean, you’ll have to use it for five consecutive days to see proper results. You can expect your drain pipes to be completely unblocked and free of sludge within three or four days.

However, the good news is that regular use- even just on a monthly basis- will keep the black sludge at bay for evermore. 

To sum all that up, Bio-Clean is another great way of blasting that black sludge away. With up to 100 treatments in a 2lb canister, this multi-purpose formula- you can even try it on your cat’s litter tray- is a great investment. 


  • Environmentally friendly formula containing no hazardous chemicals. 
  • Completely clears drains in days
  • Acts as a preventative when used regularly on drains. 
  • Multi-purpose


  • Not as fast-acting as some drain cleaners. 
Bio-Clean Drain Septic 2# Can Cleans Drains- Septic Tanks - Grease Traps All Natural and 100%...
  • Special combination of natural microbes and enzymes that DIGESTS dead organic waste found in your...
  • Eliminates costly backups. Up to 100 Drain Treatments.
  • Environmentally friendly and safe.

RID-X Septic Treatment

RID-X Septic Treatment, Septic Tank Treatment, 6 Month Supply Of Liquid, 48 oz

RID-X Septic Treatment is one of the most powerful and effective drain unblockers out there.

There’s a reason that it is voted the number one brand by septic professionals, a fact which the front of the bottle proudly boasts.

As with some of our other formulas, RID-X Septic Treatment uses a formula that is 100% made up of natural bacteria and enzymes, making it gentle on both pipes and septic tanks. 

Designed specifically with septic tanks in mind, this formula contains billions of enzymes that will break down sludge build-up in your pipes and in your septic tank with absolutely no trouble at all.

Whatever is in the black sludge clogging up your drainage system, this formula has the enzymes to break it down. Grease, toilet paper, you name it, it’ll deal with it. 

It’s a cost-effective option, too. Just 8 ounces of this drain cleaner gives you up to a month’s worth of clean, unblocked pipes.

It’s low maintenance, too, requiring just one use every month in order to achieve the best results. 

It should be noted that while this will free your pipes and septic tank from black sludge, it was designed to be flushed down the toilet, and is less effective when used in sinks.

Having said that, it’s still a great option, particularly if it’s your septic tank that is the source of your black sludge problems. 


  • Number one rated by septic professionals. 
  • Can break down the worst blockages.
  • Low maintenance, needing only one treatment per month to be effective.


  • Most effective when flushed down the toilet. 
  • Can take a little while to see results.  
RID-X Septic Treatment, Septic Tank Treatment, 6 Month Supply Of Liquid, 48 oz
  • #1 BRAND septic professionals have used in their own tanks
  • BREAKS APART SEPTIC WASTE: RID-X is specifically formulated to break apart toilet paper, grease and...
  • 100% NATURAL BACTERIA AND ENZYMES: Gentle on pipes and tanks
  • EASY TO USE: just add to toilet and flush!

Thrift T-100 4-in-1 Granular Drain Cleaner

Thrift T-100 Alkaline Based 1-Pound Granular Drain Cleaner,Red

Unlike most of our previous products, Thrift T-100 4-in-1 is not a gel or liquid but is instead made up of concentrated alkaline granules.

Being an alkaline formula, Thrift T-100 contains no acidic ingredients, making it safe for use on most household surfaces including metallic, porcelain, and plastic fixtures and fittings. 

The ‘4-in-1’ aspect of the product’s name comes from its multi-functionality. It works equally well on drains, sewer lines, septic systems, and grease traps.

Where Thrift T-100 really shines, though, is cleaning out drain lines. By following the instructions on the back of the bottle, you should be able to clean out a drain line in less than a minute thanks to its fast-acting formula.

Just remember to mix it with hot water, as that is what activates its degreasing and cleaning properties. 

In addition to this, the formula is good value for my money, odorless, and is made in the United States, so you know your purchase will be supporting American jobs and families.

It might not be a product with the biggest brand name, but as products for getting rid of sludge and blockages go, you’ll struggle to find many better. 


  • Easy to use. 
  • Deals extremely well with kitchen drain waste.
  • Odorless. 
  • Effective at unblocking drains, sewer lines, septic systems, and grease traps.


  • Not safe on all surfaces.
  • Not ideal for use in toilets or garbage disposals. 
Thrift T-100 Alkaline Based 1-Pound Granular Drain Cleaner,Red
  • This product is highly durable
  • This product adds a great value
  • This product is manufactured in United states
  • THRIFT is the only four-solutions-in-one product that works on drains, sewer lines, grease traps and...

Rejuvenate Drain Pipe and Garbage Disposal Cleaner/Deodorizer

Rejuvenate Garbage Disposal and Drain Pipe Cleaner Powerful Foaming Action and Removes Garbage...

This product is quite different from our previous ones. You know those tablets you use when doing your laundry? Well, think of these handy little pods as the drain cleaning equivalent.

They’re nearly just as easy to use. 

Each tablet contains a powerful formula that uses a foaming action to break down grease and food remnants.

Rejuvenate Drain Pipe and Garbage Disposal is at its best when used on kitchen sinks and garbage disposals, as the name suggests.

These tablets also neutralize foul odors and leave your sinks smelling pleasant, with hints of lemon and lavender. 

Although these tablets do contain enzymes to aid the breakdown of food waste, the product also contains damaging caustic chemicals, so you’ll have to take care when using it and keep it out of the reach of children and pets.


  • Easy-to-use, convenient pods. 
  • Powerful foaming action works wonders in breaking down food waste.
  • Has a pleasant odor.


  • Contains harmful chemicals.
Rejuvenate Garbage Disposal and Drain Pipe Cleaner Powerful Foaming Action and Removes Garbage...
  • Instantly cleans, maintains and deodorizes kitchen garbage disposals
  • Powerful foaming action scrubs away built-up food, grease and odors
  • Enzymes help break down food waste reducing frequency of septic tank pumping
  • Use weekly to maintain your kitchen disposer and drains

Buyer’s Guide

It might seem like a simple task, but there are more factors to consider than you probably realize when buying a drain cleaner to break down black sludge.

Here are just some of the factors you’ll need to consider: 

Type Of Drain Cleaner

You might be surprised to learn that there are a bunch of different types of drain cleaners. The most common types are liquid and gel products.

Some would argue that the reason this type of drain cleaner is most popular is because it is most effective.

Because of their composition, these drain cleaners travel through your drainage system with ease and can tackle blockages located even in the hardest to reach spots. 

You can also get powdered drain cleaners and drain cleaners that use a foaming action, but many people suggest that these are less effective on black sludge.

Because the sludge itself is viscous, it needs a similarly viscous product to latch onto it and break it down. This viscosity is something that powder and foam products tend to lack.

That’s not to say they won’t do the job, but they do tend to take longer to work. 


The next thing you need to consider is the formula. There’s no doubt in our minds that the best products for getting rid of black sludge are those that have an enzyme-based formula.

These tend to be a little more expensive, but they get the job done best.

That’s because these formulas contain the natural ‘antidote’, if you like, to black sludge, packed as they are full of enzymes that break down the organic waste that comprises black sludge.

Many drain cleaners of this type also have a preventive effect with regular use, stopping the black sludge from being able to form and block your drain again. 

The other principal type of formula used in drain cleaning products is a chemical formula.

These tend to be cheaper than enzyme-based products and are certainly effective, with many able to clear blockages in mere minutes.

However, the chemicals that these products contain are generally caustic, and although they may be advertised as ‘safe’ for use in your drainage system, they may only serve to damage it over time.

While you may really, really, want to get rid of that black sludge, is it really worth risking damaging your pipes for? You’ll only end up incurring more costs by calling out a plumber. 

Another reason to avoid these products, if you can, is that the chemicals they contain can be hazardous to your health and the health of your family. 


The best drain cleaners shouldn’t need you to use huge amounts of product to get the results you want. After all, you don’t want to have to keep rushing out to buy more all the time!

Of course, there’s also the fact that drain cleaners that require a little product will probably end up being more cost-effective, even if the initial outlay is higher. 

In terms of overall value, it’s definitely worth considering how much product you get for your dollars.

You might think you’re getting a great deal, but if you’re getting a lot less drain cleaner than similar, more expensive products, you might not be getting such a great deal after all. 

Some brands offer money-back guarantees if you are not satisfied with the product’s results, so we recommend picking a product that has one.

It’s a safety net if the product doesn’t work for you, sure, but it’s also a good sign when a company stands by its product. 

Final Thoughts

That brings us to the conclusion of our article looking at the best drain cleaners for black sludge.

There are some genuinely fantastic products on this list, and hopefully, armed with the information you’ve learned here, you’ll be able to go out and select the product for you with confidence.

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