Oh, here's a fun fact: You should rinse your mouth out then wait for at least 30 minutes to an hour before brushing your teeth after vomiting. Stomach acid is actually strong enough to weaken tooth enamel. So you should not brush your teeth right after vomiting as the enamel can be damaged. But if you rinse out the acid with water and wait it is neutralized and the enamel hardens again. No mouthwash, food, or liquid other than water either.