How to Choose and Use a Drain Cleaner

Got a clog? From plungers and drain snakes to chemical and enzymatic cleaners, here's what will clear your pipes.

Water flowing down a sink drain. Photo: Siegfried Layda/Getty Images

What goes down the drain doesn’t always go with the flow, so to speak.

And when it doesn’t and there’s an obstruction, you’ll likely have to stop using that drain until you get the gunk out, whether it’s grease and food in your kitchen sink or hair and soap scum in your bathroom tub.

To help you tackle the dirty work, this guide will walk you through the various types of decloggers, including plungers and snakes, and liquids and granules you pour down a drain. We’ll point out each type’s pros and cons, safety precautions you might need to follow in using them, and any other tips that can help you decide what to use to fix that stuck drain.

Try a Plunger First

To protect your plumbing, you might want to try a mechanical clog-remover first (especially with a toilet, because the heat of a chemical reaction can crack porcelain). A plunger may work if the blockage is in or near the trap, the U-shaped section of pipe below the drain, according to Charles White, vice president of regulatory affairs for the Plumbing-Heating-Cooling Contractors National Association (PHCC), who has more than 30 years of plumbing and HVAC experience.

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Cup plungers work best for sink and tub/shower drains, but for a toilet, you’ll want a flange plunger, which has a soft rubber flap on the bottom to create a better seal in your toilet drain.

But a plunger may work without cleaning the line, which may lead to yet another clog. Snakes are better at cleaning residual sludge from pipes, White says. They feature a metal cable that you feed into a pipe, with a corkscrew-shaped spring on the end designed to hook onto the clog so you can pull it out. You’ll want to wear safety glasses and gloves while using a snake, because standing water and debris can splash from the drain during removal.

Fast-Acting Chemical Cleaners

If you’re looking for speed and simplicity, chemical cleaners that you pour down a drain can tackle a clog in half an hour or less. As their name suggests, these products rely on chemical reactions to break up a blockage. Although there are three kinds of chemical cleaners—caustic, oxidizing, and acidic—acidic products, such as Zep Sulfuric Acid Drain Opener, rely on extremely hazardous chemicals and are generally used only by professionals.

Caustic Drain Cleaners
Such as Drano (liquid; at Amazon and Walmart) and Thrift (granules; at Amazon and Walmart)
Cost: From about $5 to $20
Caustic drain cleaners can include ingredients like lye (sodium hydroxide), caustic potash, and/or bleach. Lye’s corrosiveness allows it to break down grease and organic material, such as hair and food particles, while potash (a type of potassium salt) helps to speed up the decomposition of that organic matter. Caustic drain cleaners are especially effective on grease blockages.

Oxidizing Drain Cleaners
Such as Liquid-Plumr Industrial Strength Gel (at Home Depot and Lowe’s) and Zep 10 Minute Hair Clog Remover (at Home Depot and Lowe’s)
Cost: From about $10
Oxidizing cleaners can contain ingredients like bleach, nitrates, and peroxides to make quick work of a clog. On a molecular level, the active chemicals work to strip electrons away from the stuff stuck in your drain, a reaction that produces gas and heat as it loosens the obstruction. In general, oxidizing products are most effective on organic materials like hair and food and less so on grease.

The Downside of Using Chemicals

While they’re generally quick and effective, chemical drain cleaners can be hazardous to use. Caustic cleaners, in particular, can cause chemical burns if they come in contact with your skin, and be sure to check labels and take precautions as some products may give off harmful fumes. If you use one, follow the instructions carefully, including keeping children and animals away from where you’re working.

“Use protective equipment—rubber gloves, safety glasses, face shields, aprons, that sort of thing,” says Dave Frame of Bob Frame Plumbing Services Inc., and PHCC president-elect. “Chemicals can attack carpets, flooring, or other finished surfaces, so be careful not to spill.”

Proper ventilation is also key. White recommends opening a window; if there isn’t one, turn on a ventilation fan. You should also never mix multiple drain cleaners, DIY or otherwise, or use them in with other chemicals, like bleach. Look for safety and health warnings for a chemical drain cleaner on its safety data sheet. (Check the manufacturer’s website or search the SDS database.) 

Chemical drain cleaners aren’t likely to be a problem for your pipes, whether plastic or metal, if they’re installed to code and you follow the directions on the product packaging, says Paul Abrams, a spokesperson for Roto-Rooter.

“However, sometimes homeowners replace undersink drain pipes with flexible/expandable drain pipes that are made of light-gauge plastic and not up to code,” Abrams says. “Since chemical drain cleaners create heat, they’ve been known to melt through these cheap replacement drain pipes if the chemical sits inside too long.” This could also be a concern in older homes with plumbing that’s old and rusted. 

Sodium silicate, a corrosion-inhibiting ingredient in Drano and Liquid-Plumr, may help protect metal pipes, but you still have to follow the instructions exactly.

Safer Option: Enzymatic Cleaners

Enzymatic drain cleaners offer a gentler alternative to the harsh chemicals found in many drain cleaning products. Essentially, bio-enzymatic products break down stuck material into smaller particles, which beneficial bacteria then digest. For the best results, look for a product that targets the type of clog you have—hair, soap scum, food, and/or grease.

Enzymatic Cleaners
Such as Green Gobbler (at Amazon and Home Depot) or Bio-Clean (Amazon, Bio-Clean, and Walmart)
Cost: From about $12 to $70
These cleaners aren’t as fast-acting or as effective at dissolving clogs as the others, Abrams says. They need to be left in a drain for several hours or even overnight, and you may have to apply them more than once to fully clear an obstruction. But they’re safer for your pipes than chemical drain cleaners. And if you have a septic system, these products are not only safe, they can be beneficial, helping replace lost essential bacteria that aid in breaking down waste—sometimes from the use of other types of drain cleaners, Frame says. In fact, they can be used preventively to keep a septic system healthy.

Thanks to their safer ingredients, these cleaners are also more eco-friendly. Although water treatment facilities act as a barrier in removing household chemicals before they enter the environment, the process isn’t completely effective and some do get through, potentially posing a risk to fish and wildlife.

If you’ve tried mechanical methods and a drain cleaner to no avail, your next step should be to call a plumber.

“It is not unusual for what appears to be a local stoppage to actually be a stoppage in a larger branch or building drain,” White says. “If that is the case, it can become a very messy job in a hurry.”

A plumber will probably conduct a pipe inspection before using heavy-duty tools, such as a motorized drain snake or hydro-jet, to remove the clog. 

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Headshot of freelancer Camryn Rabideau

Camryn Rabideau

Camryn Rabideau is a freelance writer and product reviewer who specializes in home, kitchen, and pet products. Her work has appeared in Forbes, USA Today, The Spruce, and other publications.