There’s nothing worse than having a stubborn stain that won’t budge, no matter how many times or how hard you scrub. A particularly difficult stain to get rid of is the one left by your daily tea or coffee, which leaves a delightfully brown ring in mugs and cups.

Coffee stains are hard to remove because they contain tannins, natural plant compounds that act like dyes and bind tightly to surfaces. However, cleaning fan and TikTok creator Lou revealed that there’s a simple household item that may just do the trick – and it’s probably not what you’d expect. In a video from September, Lou said: “Here are my favourite cleaning hacks to help you clean smarter and not harder. Because contrary to popular belief, I like to spend the least amount of time cleaning as humanly possible.”

How to clean mug stains

Instead of the usual suspects of baking soda and vinegar, Lou recommends using an item you’d most likely find in the bathroom. When tackling stains inside mugs or cups, Lou suggested using denture tablets.

If you’ve tried scrubbing off unsightly tea and coffee stains to no avail, Lou recommended popping a denture tablet into the cup with some warm water. Allow the denture tablet to fizz and dissolve.

Denture tablets can work quickly, so it may take as little as three to five minutes. To make the most of the tablet’s cleaning power, you can leave it for between 10 and 20 minutes to tackle stubborn stains.

Once the stains have disappeared, give the mugs a quick rinse, and they’re ready to go. Lou explained that you can also use denture tablets to refresh kitchen sink drains and toothbrushes.

Lou said: “They’re small but hella mighty.”

Why do denture tablets work?

Denture tablets are actually incredibly versatile when it comes to cleaning, as they contain many of the same ingredients that you’d find in other cleaning products. Using oxidisers, peroxide-based bleach, baking soda, and washing soda, the tablets are designed to clean porcelain and acrylic dentures.

The Spruce explained that the tablets can also “effectively” tackle stains on items such as “china, porcelain bathroom fixtures, glass and ceramic bakeware, and most glass or metal small appliance interiors”.

Martha Stewart also explained that denture tablets are good to tackle hard-to-reach crevices when cleaning. When the tablets fizz, they can delicately lift stubborn residue.

Claire Helen, a professional cleaner and founder of SisterPledgeCleans, told Martha Stewart: “They usually contain citric acid and bicarbonate of soda, which create the fizzing action. That effervescence helps lift debris from crevices and tight spaces without heavy scrubbing.

“They also contain a mild oxidising ingredient, often sodium percarbonate, which helps break down stains and has a gentle whitening effect.”