This Internet Hack Says a Dishwasher Tablet Will Easily Unclog Your Sink—So I Asked a Plumber (And Tried It!)

A slow-draining (or totally clogged) sink is one of the more frustrating problems in the home. While most clogs occur slowly over time, the effects—a sink full of gross water and the accompanying frustration—somehow always feel sudden. That’s exactly why I normally keep a bottle or two of Drano Max on hand (and of course, my plumber on speed dial). To my chagrin, my go-to drain-clearing product was absent in my below-sink cabinet when I most recently needed it.

So I did a little research to learn if anything I had on hand would do the trick—and I found one compelling solution buried deep in the internet. Apparently, dishwasher tablets can unclog kitchen sinks in a pinch (and I just happened to restock!). It was the sink in my laundry room, not my kitchen, that had overflowed, but I was curious nonetheless. How did it work, and would it be effective in other areas of my house?

Chalk the potential up to the dishwasher tablet’s grease-cutting ingredients. Paul Abrams, a representative from Roto-Rooter Plumbing & Water Cleanup, says he’s not surprised people use dishwasher tablets in their drains, given they’re made with phosphates, enzymes, alkaline salts, and oxygen-based bleaching agents. “These ingredients are effective at dissolving grease and stubborn, sticky food waste, which are the most common building blocks of kitchen drain clogs,” he says. 

If you habitually use dishwasher tablets in your actual dishwasher, you might already be reaping the pipe-cleaning benefits in your kitchen sink—Abrams says most dishwashers drain into the kitchen sink drain. But don’t expect a tablet to magically clear your drain. Abrams says it’s doubtful a tablet will clear a sink clog as quickly or effectively as the leading liquid drain opener products, which are far more caustic and corrosive. 

“Purpose-designed clog busting products use lye as the active ingredient to cut through tough drain clogs as quickly as possible,” he says. “However, if you aren’t in a hurry and don’t have access to a liquid drain opener, a dishwasher tablet or two may be a reasonable substitute in a pinch.”

Of course, before I ran to the hardware store for a Drano refill, I wanted to see how well the tablets worked in the drain that was actually clogged. So I placed a pod in the sink, let hot water run on it for about 30 seconds until it dissolved, and waited to see if the sink would drain. It didn’t. (I’m not surprised, since there wasn’t food waste or grease in my laundry sink.)

My bathroom sink wasn’t totally clogged, but it tends to run slowly, probably because I don’t routinely clean the drain stop (whoops). I attempted the same method there, without any noticeable results. (Unfortunately, dish soap ingredients don’t mitigate hair, which is the primary problem in my bathroom drains.) 

Next time, I’ll definitely take Abrams’ suggestion and use traditional drain-clearing products—which reminds me, I need to go to the store today and get my Drano. But it’s nice to know that in a pinch, I can refresh my kitchen sink with a dishwasher tablet—if anything, it’s fun to watch the colorful ingredients dissolve in the sink!

One note from Abrams, if you try the trick in any drain: If you end up having to call a plumber to unclog your sink, be sure to tell the plumber if you put products down the drain. They will appreciate the information so they can better protect their eyes and skin from the chemicals while working to clear the clog. Safety first!