"Pepto-Bismol is made in chewable tablets and swallowable caplets, but is best known for its original formula which is a thick liquid. This original formula is a medium pink color with a strong wintergreen or cherry flavor."
"Or" emphasis mine. I'm speculating that the cherry flavor is the one that says "cherry flavor" on the package (that's Ms. Hawking to you), so that leaves wintergreen. You might want to ask about "chalky" flavors in the DIY forum. I know cotton candy, sweet tarts and pixie dust sometimes have a "dry" taste.