Fwiw, I have suffered with dry mouth for years as a side effect of one of my daily migraine meds. Because of this I learned that saliva has an enzyme (lysozyme) that kills bacteria in your mouth, and that those with decreased saliva need to be particularly diligent with their oral hygiene regimen. I'm wondering, therefore, if the increased dry mouth from vaping could be contributing to the occurrence of tonsiloliths which contain bacteria (among other things). If so, increased hydration and Biotene may help. The acidophilus seems like a viable option as well.
