Sedonia!

Yes, how about next time around. You already have the P & B. It's not like one time of colon cleansing is the end of the story, anyway.

The differences are:
Psyllium is like "scraping" or "scouring" the walls of the intestines. Bentonite is absorbing toxins, drawing things to itself somewhat magnetically.
Cascara sagrada is a an herbal irritant (can be addictive) that forces the muscle walls into peristalsis.
Magnesium oxide ( Oxypowder /colosan) liquidifies the wastes, literally turning colon contents into water and CO2. Also, the magnesium draws water into the colon, so there is a lot more water in the colon. This is why you "gotta go" and/or have very soft or liquid poo. Water in the bowels is important, either via magnesium or from colonics. The hardened plaque in the bowels needs to absorb water to be softened, in order to break up or come out. This is why some people didn't get hardly anything out in their first colonic or two. The plaque was merely absorbing the water but had not yet been softened enough to be eliminated.
BUT things like psyllium can assist in breaking up and moving the debris, and the Bentonite can assist in preventing these toxins, which have been stirred up, from being reabsorbed. And the psyllium prevents the now toxic Bentonite from just sitting in the colon, hardening itself.
So you can see that these things can all work in conjunction with the others (although not necessarily at the same time). Cascara sagrada and, to some extent, psyllium are rather harsh on the intestines. And the magnesium oxide can potentially create mineral imbalances.
Oh, another difference, from the external physical perspective: psyllium can create bloating/puffy stomach. Magnesium oxide usually gives a flatter stomach.
Don't forget that several cups of warm water on an empty stomach can be a dear friend for creating peristalsis and hydrating the contents of your bowels!
Hope this rambling makes some sense!

(p.s.)Oh, and I don't find colosan (powder) disgusting at all. It's slightly chalky water, no flavor, down the hatch, and then lemon water, which I like anyway.
(p.p.s.) You definitely want to get the colon cleansed before the parasite cleansing starts, because as the parasites are killed/released you want them to EXIT as soon as possible! Not only are they bad on their own, but once dead they release bacteria and viruses and eggs that can begin to spread, of course the cloves should take care of the eggs but you definitely don't want the parasites lingering. Also they can make you feel sick if they are slowly lingering in the intestines. Read some of Dr. Hulda Clark 's info about parasites if you want more information on this.