Although I'm not going to disagree that you should follow Doctor's orders in regards to the colonoscopy prep (I know u said that's not why you were asking anyway, lol), I will say that I have reached total clear before after using enemas. Your problem may lie in how long you waited between enemas. I only do enemas 3-4 times per year (so probably am "dirtier" than most folks on here when I start) and usually only do a series of three 2-quarts, but on a rare occasion I take five, and at the end of the fifth, I am releasing clear water, or maybe a little yellowish water. However, on some occasions, I am already mostly clear by the end of the third. Also, I normally use only tap water, which works fine...only occasionally I'll put salt in it, and also normally use a different position for each one...left side for the first, knee-chest for the second, and lying on back for the third).
I personally feel that "colonic irrigation" and "colon hydrotherapy" are nothing but a medical racquet (I mean, really, $70-$100 for an overglorified enema? Sorry if there are any therapists reading this). They are EXACTLY the same as a high enema...if you read most therapist's sites, they will say that "enemas only clean the 'lower part' of the colon while the colonic cleans the entire bowel", but they are really talking about the common Fleet enemas, and assume that most people these days don't realize that you can take a larger enema at home (and, sadly, most people don't realize that!). But for those of us who are smart enough to know better, save yourself the embarrassment and money and do it yourself at home. Outside of having it flow constantly into you, and have it sucked out of you in a tube and being able to see the "results" as they flow out, there really isn't any further benefit to it for us enema users.
I mean, I might pay $25 for it just to experience the steady flow and to see what its like to have it all sucked out through a tube, but not more than that, lol. 😎