Alcohol should be volatilized, the water cup stained with alcohol in time to wash the water cup with flowing water for a while, brush the cup with a brush, and then soak with warm water, boiling water a bubble is good.
If you feel that it is not thorough, you can also burn a pot of boiling water after brushing, boil the cup in boiling water, and cook it for two minutes on a low flame, it must be cleaned thoroughly.
You can put a little toothpaste on your finger, and then wipe it on the mouth of the cup, wash it with toothpaste, rinse it with water after the toothpaste is evenly smeared, and finally soak the cup in hot water for a minute to disinfect it.