I continue to enjoy my Model B in 18 Mildly Firm, although 10 Soft and 00-50 Plus Soft should work fine too. I don't think softness/firmness should be much of an issue, unless people are getting doubling back at the upper sphincter with the two softer materials. Is anybody?
I also love the Model B for non-enema use. I like to use it as a beyond-the-rectum butt plug. I love to leave it inside me and clench down on it over and over:
Me: clench, relax, clench, relax, ...
My Model B: in, out, in, out, ...
My penis: longer, longer, drip, drip, ...
It feels so good I can do it for hours. My sphincters and pelvic floor muscles are getting a real workout.
I think the Model B helps with a physical therapy exercise that I'm supposed to do at home as therapy for my my SI-Joint Pain Syndrome. A bad cycling accident stretched or tore the big ligaments holding my right pelvic bone to my sacral vertebrae, and now it moves too much and pinches my right sciatic nerve. My lovely physical therapist gave me an exercise to do to stabilize my pelvis by strengthening my pelvic floor muscles. The exercise is to repeatedly do exactly the same clench that feels so good with the anal insertion of a Model B, certain other anal toys, or a man's penis. I'm not making this up. When my pretty physical therapist explained it to me and I tried it, I jokingly said, "I've got it. Oh yea! I love the way this feels!" She blushed and laughed. I think she likes doing it too. I've still got the exercise sheet that instructs how to do this exercise, but I don't need it of course.
Physical therapists should prescribe Model B's for their anal erotic patients with SI-Joint Pain Syndrome! They would far more faithfully do this exercise at home as directed. I really think my Model B is helping my pain SI-joint pain, and now I bet I've got the strongest pelvic floor muscles in my zip code.