Name one man who masturbates who says they wouldn't do this, and I'll show you one man who is a bold-faced liar. Its really no different than jerking off, except it seems freakier cause we can't do it. But if guys around the world were capable of it, it would just be the accepted norm that you did this to masturbate, and there wouldn't be an issue with it whatsoever.
I do believe there are some guys who don't jerk it, though. I'm thinking those Shaolin Monks don't, which is why they can do what they do.
BTW just because you would suck yourself off doesn't mean you'd have to drink your jizzle. That's totally separate!