You should rinse your mouth always after drinking apple cider vinegar.
Apple cider vinegar is acidic and can erode your tooth enamel so it's important to rinse your mouth with water after drinking apple cider vinegar to minimize and prevent damage to your teeth.
When drinking apple cider vinegar you should also dilute it with water before you drink it.
You can also use straw to minimize the contact of the apple cider vinegar with your teeth.
And also avoid brushing your teeth right after drinking apple cider vinegar as the enamel gets temporarily weakened from the apple cider vinegar.
Wait around 30 minutes to an hour before brushing your teeth.
Apple cider vinegar is good for mouth bacteria as apple cider vinegar has antimicrobial properties that may help kill oral bacteria responsible for bad breath and tooth decay.
A study also found that rinsing with diluted apple cider vinegar reduces plaque buildup on your teeth as well.