Silicone can be grippy and irritating on the urethra, and the flexibility reduces the pleasure anyways. Just get a full set of rods and start with 4 to 5 mm, any adult cock should be able to take that. And yes, go slow of course! I’ve never gotten a prostate orgasm from it, but having my glans stretched out with a thick rod makes it 100 times more sensitive; very mind-blowing orgasms!

Also you dont need sterile sugical lube, its thick and dries out fast. I recommend LubeLife brand lube. DO NOT USE SILICONE BASED LUBES they do not feel good inside the pp.

Also, im not necessarily recommending this, but im super lazy with cleaning them (just wipe with a paper towel when done) and I’ve never had a uti or other problem in 20 years of sounding.