2. Put a few slices of lemon peel and orange peel in the cup, or drop a few drops of vinegar, and then soak it overnight; The skins of apples and other fruits can be removed by dipping a little salt in the skins and then scrubbing the cups.
Soak the rag in milk to wipe the cup, and the dirt will be removed soon.
4. Soak in Taomi water for one night. This method is also applicable to glasses, stainless steel cups and ceramic cups.
5. Clean quickly with toothpaste. Rinse the inside and outside of the cup with clear water first, then apply toothpaste on the cup, scrub it hard, and then rinse it with clear water.