First of all, most women masturbate outside the vagina, at least as their main stimulation. See, there this little thing called the clitoris. It a little wonder gizmo that can do just about everything. Anyway, seriously--I never stop having sex or masturbating on my period. Luckily I have never been with a guy or girl who was bothered by this. But then, everyone I've been with has been very well educated (about the body and sexuality) and very mature and open-minded. Sure, it can be a bit messier but it's not harmful or painful or any more "unsanitary" than any other fluids and juices that are the result of sex. As some others have said here, a woman is often more horny during parts of her period and can have slightly different orgasms.
I think your actual question is a bit confusing and I'm not clear what you are trying to ask, but if I take it literally and describe to you how I achieve orgasm while on my period--not counting "intercourse" (for whatever reason) and trying to fidget with a tampon (also for some strange reason); then I would have to say that I do it the same way as always. My fingers on my clitoris while doing anal sex with my lover. That is and always has been my favorite way to achieve orgasm, period or no period. I would masturbate the same way too. I love my clitoris. It's a handy little friend.