El Tejon:
Have you have a Lovecraftian Horror similar to those in the ad emerge from your own pesonal Stygian Depths when using such a colon cleansing product?
>>>TMI WARNING<<<
FWIW, I am somewhat inclined to call, "snakeoil" on the colonic cleansing deal.
I had some, ah, "issues" down south a while back that necessitated a sigmoidoscopy and colonoscopy. The pre-"oscopy" regimen included refraining from eating, lots of clear liquids, a powder that make me feel as if I were going to generate enough thrust to go into low earth orbit, and a doubled-up Fleet enema that also was on the "not" side of pleasureable. I noted nothing "...the consistency of truck tire rubber. It's that hard and black." during my porcelain carnival ride.
Then, my doc was cool enough to ask (during a procedure), "Wanna look at your innards? No extra charge." I got to see my colon from the inside on video. I was commended on the thoroughness of my pre-"oscopy" regimen. No stuff "...the consistency of truck tire rubber. It's that hard and black." from whence the sun don't shine. Nothing but a couple polyps that the doc excised.
Maybe the raw-meat-eaters need to go to the vet and get some puppy wormer, do the math, and apply it to themselves. I'd think the liklihood of ingesting live parasites or thier eggs greater than any "truck-tire rubber" accumulation in their bowel.
Either way, good luck with all that colon-blowing.