If it was me, I'd book a full-blown SP for this sort of service, rather than confuse the hell out of an Asian rub n tug masseuse. Talk to the SP before the meeting and tell her exactly what you're after. If you're a regular at the parlour, you might have some luck though - This definitely isn't something that I'd ask for on my first visit. The golden rule as ever though is COMMUNICATION. If you don't ask, you don't get. Good luck and let us know how you get on.
The only time I've experienced anything similar was with the magnificent Tess McGill when she was still in Manchester. She was a proper exhibitionist, and liked to get herself warmed up at the beginning of a session. It was always a means to an end though, an aperitif before the main course.
Personally though, I think you're crazy - why the fuck would you swap a glorious HE for a boring old DIY wank? The only reason I go for a massage is the chance to exchange my heavily calloused fist for a delicate feminine palm. For a brief transcendent moment, I become a wankee, before turning back into the sad old wanker that cruel fate has decreed I must be for the rest of the time. Anyway, what do I know? You do you, literally and figuratively.
