A few flesh tunnel questions.

I want to try flesh tunnels to help my phimosis. I've measured my foreskin opening and it's about 20mm in diameter before any kind of stimulation (can be retracted partially over the head of the penis right off the bat) but it expands to about 30mm in diameter during masturbation when it is naturally lubricated and worked which basically lets me get it all the way over the head of the penis though its extremely tight and uncomfortable, also my frenulum feels very tight when I do this.

First, should I be putting in the flesh tunnel from an unstimulated 20mm state or should I first stimulate the foreskin to 30mm and then put in the flesh tunnel? This would also let me know what size flesh tunnel I should be starting out with.

Second, I've read articles about ear lobe stretching, and it seems to be a common belief that silicone as a stretching tool is highly discouraged because it is a porous and tacky surface which could cause infection. I'm a little confused if this applies to foreskin stretching. Ear lobe stretching seems like the same concept as foreskin stretching and I've read that many people here use silicone tunnels because it is the most comfortable material but I haven't seen the issue of silicone being porous discussed. I'm guessing frequent cleaning of the flesh tunnels will take care of any possible bacteria growth? Would an antibacterial cream like Neosporin be acceptable for cleaning flesh tunnels?

Thanks for your time guys.