Just to update my post above, I tried out the 20" Cleanstream tonight and had fun! I started with a couple large fills from my regular shower nozzle to clear things out in preparation for a deeper insertion. After hooking up the 20", the first thing I noticed is that the bore of the nozzle seems a bit narrower than the bore of the 10" Cleanstream, so the same flow of water I'm used to seemed to jet out more forcefully in a narrower stream. I made sure to turn it down to a much more gentle flow for this reason. Lubing the length of it, I was easily able to slip it in up to the top of my rectum, and with some relaxing of my anal and rectal muscles and very gently easing it against the bend, I was quickly able to make it around the turn and several more inches easily slipped up deep into my sigmoid colon. I could really feel the water starting to fill me up now, and I slowly pushed the remaining length inside, all but an inch or so of the tube. As someone noted earlier, this one definitely goes straight up your ass. There was no mistaking the sensation of it snaking up through my descending colon on my left side and filling me from deep inside, it doesn't fold back over at all. I kept the nozzle inserted fully as it continued to trickle warm water into me over several minutes, feeling it continue to flow up through my gut until my belly was about as full and tight as I could comfortably take. My usual enemas are 3 to 3.5 quarts and often 4, and I could tell from the sense of fullness that I was easily up to 3 quarts and probably more before I decided to quit.
After a long release on the toilet, I wanted to try it out for the kind of at-home open colonic I'm used to in the shower, holding the nozzle in and releasing around it once I'm full before refilling and repeating many times for a thorough deep cleanout. Once again, I was easily able to work the whole length into my colon with barely a push, and I felt myself filling up tighter with water before relaxing my anus and pushing out. It was easy to keep the length of the nozzle held in place without it being pushed out of my rectum and colon as I expelled, and I spent quite a while in the shower feeling the water filling up my colon before rushing back out of my ass - I like the sensations of expelling large volumes over and over. The repeated deep flushes really did seem to clean me out more effectively, bringing out even more small bits of leftover material from deep inside. Overall, compared to my favorite SN 18" shower shooter, this one seems to be more stiff in the tip, and because of its narrowness I could more easily feel the smaller tip of it pressing at the walls of my colon when I tried to work it in and out. The slim diameter also made it easier to expel water around while I held it in place in my anus. The narrower width does make for an easier deep insertion, but I do prefer how the width and bulbous section of the 18" SN help to work open the bend to my sigmoid. I like the feelings of that one as its bulges pass through my anus and colon, and its more blunt tip seems to be comfortable as well. While I'll probably continue to prefer that one, the new 20" Cleanstream was a fun way to get quite a deep colon insertion and several very large enemas. I liked this one!