My oncologist said an occasional drink was okay and although I have abstained from alcohol since 2007, I used to enjoy non-alcoholic beer on occasion. After my sixth surgery in 2019 I visited a naturopath who was willing to work with me in conjunction to my other physicians. She suggested that I had silent reflux and placed me on a low acid diet. This involved giving up soft drinks, non-alcoholic beer and a large number of foods such as tomatoes, citrus, pineapple, tart apples, mango, and most berries. It also ruled out seltzers and any carbonated beverages. It limits chocolate, coffee, and tea. Although i did have a recurrence of cancer in 2020 and had 3 more surgeries, radiation, and chemo, I have stuck to this diet and my mouth has been calmer than it's been since 2010.
I'm not saying that all oral cancer survivors should give up alcohol or non-alcoholic beverages, but I know that in my case it made all the difference.