I've tried Bentonite + psyllium = didn't work, tried Oxypowder , didn't work, prior to that enemas - didn't really work (all while fasting ofcourse). Master cleanse + swf didn't work because the water wouldn't pass thru my clogged colon and got stuck halfway thru. Best thing is proffesional colonc - you must be fasting at the same time (MC will do), and on days you don't have a colonic do SWF (Salt-Water-Flush) if you can't. Since i couldn't, i did enemas.
Ofcourse there are thousands of people that did great on psyllium, or SWF, so all you can conclude form that is that colonics are the most powerfull, but not necesarily necesary.