My completely anecdotal experience- in fall of '07 I spent a month studying yoga in Thailand. This was before having any intention of starting a family anytime soon. There was this amazing massage place nearby where I stayed, where I went often and developed a rapport with the owner and two of the massage therapists. They provided these incredible, massages, and for some reason they really focused on my abdomen. They would giggle and tell me that I'd be a good mother someday and work on me all over, but really did stuff to my belly. I asked them once, they said they were 'moving things around', I always felt incredible the next day so just let them do their thing. I left Asia a week early to surprise DH for his birthday. I should not have been ovulating, though I wasn't charting- on birth control at the time. I got pregnant immediately. When we found out, the first thing that popped into my head was those little Thai ladies, climbing onto my belly and digging into acupressure points with their toes and telling me I'd be a good mother someday. I swear, they did something in there! Now, I've read a lot about this Mayan abdominal massage and have one friend who's had it done (for PCOS)- and I know it's not the same thing, but I do think it's pretty similar. And call me crazy, but I definitely, at least partially, credit those ladies with having conceived my son.
Again, I know it's not the same thing, but I do think what the did was similar to the descriptions of the Mayan technique I've now read about, and from my experience it hurt the way deep massage or acupressure hurts; I really like that kind of massage so didn't find it particularly painful, just something you have to really breathe through. (Nothing like bad menstrual cramps, so if there's a chance it might relieve those, it's worth it.)