Two of my friends and I are experimenting with Colonix right now and documenting our results online.
One of us has already passed some nasty stuff that you can see on http://www.experimentmonkey.com/2006/02/22/colon-cleanse-with-friends-mr-pink...
I nor my friends are affiliated with Colonix and I'll be posting what we experience on a daily basis be it good or bad.
So far it's been pretty good.