We’ve all been there. You open the dishwasher expecting sparkling clean dishes, only to be met with a swampy puddle of murky water at the bottom. It smells bad, it looks gross, and you just want it fixed.

While it seems like a logical shortcut, using drain cleaner in your dishwasher is one of the worst appliance mistakes you can make. Here is why you should never do it, and what to do instead. Drain cleaners (like Drano, Liquid-Plumr, or caustic soda) are formulated for solid pipes—think cast iron, PVC, or copper. Your dishwasher is made of rubber hoses, plastic pumps, stainless steel filters, and delicate heating elements.

When frustration sets in, desperate thoughts follow. You look under the sink, spot the heavy-duty drain cleaner, and think: “It clears pipes. Why wouldn’t it clear my dishwasher?”

Have you ever made this mistake? Or do you have a safe dishwasher drain hack? Let us know in the comments below!