I'm using dilators that came in a kit of 3 called Colt Anal Trainer Kit. The smallest one is suitable to use, though I can't get it all the way in yet. I hope to work my way up to the second one but the third one, O my, it's for a horse I think.
They are smooth and easy to use and keep clean. I had to go to an embarassing website to order them :oops:
Anyway, I do believe they are helping me.