I ordered up a set of the Huse rings, and they came in today. The smallest of them is nearly 2" wide, and took me nearly an hour to get in. I used a smaller 1" plug to close the gap inside it while inserting, and didn't remove it until I had it all the way in. I figured that'd be a good way to keep the mess to a minimum while putting things into place. Once I got everything set, I found it very uncomfortable; I had to poop before I even started, and it wasn't able to get through the hollow ring, it got all stuck inside. So, unable to actually evacuate my bowels, I had to take the thing out after a half hour. When I did, I found the diaper stained red with a small amount of blood, and I went very slow putting it in, using several other toys to open things up first.
I'm not terribly happy with my experience. I'm considering selling the two rings I didn't use (medium and large); if anyone would like them, just send me a PM. I'd sell the small one too, but I don't know who'd want to buy a used ring, even very well cleaned.