My guess is that the so-called "colon-cleansing" products cleanse the small intestine as well. In fact, I suspect that most of the mucoid plaque or old mucoid matter that comes out originates in the small intestine rather than the colon. That would explain the fact that MD's who do colonoscopies see pink tissue rather than black gunk lining the colon. I have no proof of that and would be glad to hear a different point of view, but as of now that's my working theory.
I've personally had good results with Holistic Horizons, but people seem to have excellent results with drnatura, ultimate cleanse, P&B shakes, etc. My colon hydrotherapist, who is very well-informed and passionate about cleansing, loves the Ejuva program. I believe all the above are vegan products. I haven't seen much evidence that homozone and that sort of product clean out old mucoid matter.