You can neutralize the ACV by taking a 1/8tsp of backing soda, mixing it with warm water and then gently rinsing your mouth with it. Letting the BC soak into your gums. This neutralizes the acidity of the ACV.
note: If you're over 35 you DO NOT want to vigorously swish this in your mouth because it can be abrasive. A gently swishing around is all you need. I keep mine in about 15 seconds on top and 15 seconds on bottom.
btw: If you have dry mouth at night this is also good to help control the bacteria and keep saliva moving at night.