well it's also true for cornflakes. They have a weird creepy history because the creator of them was against things like masturbation, and he suggested eating cornflakes would help.
But I believe OP was probably referring to a simpsons episode. The flanders are playing pictionary where Flanders draws cornstarch on the poster, and his wife gets the answer correct. I wasn't alive when this episode came out but probably the writers were making a joke about cornflakes by using cornstarch, but that's jst my guess.
I still wonder how the dude thought cornflakes made you not want to whack it, and how so many actually believed him (then again, [gestures broadly] maybe not).