I've read so many posts here about the horniness that can happen after circumcision, but the men are advised not to masturbate. It's got to be even worse than having an itch under a cast for a broken arm. I mean, you really want to have an orgasm, right?
Although I'm not a doctor, so you should double-check this information, I believe it is OK to ejaculate as soon as you can have an erection without pain.
The only thing you need to protect is the skin at the circumcision site. I mean, the mechanism of orgasm and ejaculation has nothing to do with that - as long as you don't stress the skin.
So, here's what you do. Find something that vibrates. Ideally, it will be a sexual vibrator, but it could be anything, from an out of balance Dremel tool to the side of a washing machine on rinse cycle. Hold your penis against it. It will make you ejaculate without ever disturbing your sensitive skin.
Interestingly, it might even help the healing process. It seems erections are the hard part (pun intended). By doing this and becoming sexually satisfied, it ought to reduce the number of unwanted erections you'll have.
Cheers! - Jeremy, Medibation.com