Why not use sterile catheters?
There are single use catheters and Foley catheters.
You can buy them at your local medical supply store or order them online.
I got into the urethra when playing with estim. There was a small probe that went in 6 inches. Putting it was hotter than the estim result. My estim stuff is in my closet.
I love sterile catheters.
I started with an 18 fr intermittent about 3 mos ago. I went to a local medical supply store. Anyway, I didn't like holding it in. I went back to the same local medical supply store and bought some 24 fr and kits. The guy said, "those are some huge catheters." I turned red and I said, "It's for my dad." LOL.
The kits have all the stuff to make it clean and safe.
Needless to say, I went on-line for my next order. I got 3 - 24 fr, one 26 fr, one 28 fr, one 30 fr. I have a 24 fr in me now. I did the 28 fr a few days ago.
I save the 30 fr and look at it and hold it for titillation. It will probably go but later.