
Mugs and cups used for hot drinks like tea and coffee can become over time. The staining agents, known as tannins, produce this stubborn mark on the cup. Whilst they may disappear if you rinse the cup immediately, if you leave it to sit, it's unlikely they'll come off.
Drinking from stained mugs is perfectly safe, but they can be unsightly, especially if you're hosting. Posting on the Tips Facebook page, Tia Macaulay said: "Does anyone know how to get rid of tea stains in a mug? I have a lovely Cath Kidston one, but I can't budge the stains.
"I also can't put it in the dishwasher. I've tried soaking it in boiling water with washing-up liquid and nothing."
The post received hundreds of comments, but the most popular hack recommended was denture tablets.
Sonia Alden said: "I use denture tablets and boiling water. Let it sit for a bit and then wash as normal. It is much safer than bleach and does the job perfectly.
"I prefer to buy the minty denture tablets, as then I can smell if the tablet has lingered and I need to wash the cup more."

Harriet Young wrote: "My Nan recommended using denture tablets as she uses them for her teeth, but also around the house for literally everything.
"They removed 15 years' worth of stains, and they are so cheap to buy."
Joanne Westwood also recommended denture tablets dissolved in hot water. Joanne said: "Old trick I learned from my Nan many years ago. Cleans teaspoons up a treat too."
When combined with hot water, the tablet will react, helping to banish the stubborn marks.
Soak the mug for around 10 minutes and repeat if necessary, although one time is usually sufficient.
Many supermarkets sell denture tablets for as little as 3p per tablet, proving this hack is super affordable.
Other involve using salt to help scrub the brown stains, as well as .
If you're looking for a chemical cleaner, Astonish's Clean and Revive works a treat, according to Mrs Hinch Fans.
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