I know nothing about this, but the few times I have taken psyllium, separately from food, I have felt overstuffed and bloated.
I've also read, here on the CureZone, that psyllium can actually cause a blockage of some kind. Even though this may be a sign of too little water, I felt that the gluey consistancy of wet psyllium wasn't for me.
I can't remember if I took Bentonite with it, but clays make me wary, too. However, I certainly recommend them for external use, and as a great tooth polish/mouth freshener. (I've heard that too much will clog the drain in your sink or bathtub...but think that would have to be a good-sized hand-full!)