1, you can put toothpaste on the rag and carefully scrub the inside of the cup, and the stain will disappear.

2. Wash the eggshell, crush it and throw it into the bottle. Add hot water, not half a bottle of eggshells, then block the bottle mouth and shake it up and down. After many times, the cup is clean.

3, the teacup has been used for a long time, and a layer of tea dirt will accumulate inside. Just dip a little salt in your hand, gently rub it inside the teacup, wash it with clear water, and rub it several times to remove the tea dirt.

There is scale in the teacup. The main component of scale is water-insoluble calcium and magnesium compounds, which can be soaked in vinegar and then wiped off with a soft cloth.