I have never heard of the special spot in your mouth thing, but that is really interesting. Next meal now i am sure I will look really funny trying to chew my food differently.
As for drinking my food, I have a pudding in a blender with extra water, ice, and some flavoring almost every morning. I usually add enough stuff for it to be two big glasses of shake, which more than fills me up. Maybe you could try this with the RTD? I have never had one so I don't know. But I do find that I need a certain volume of liquid, more than food, before I feel full.