Well, Cap’n. I have to declare TMI. What in the wide world of sports is a taint hole?
On a normal person, down in the nether region, there's a pee-place in the front and a poo-place in the back. Between the two, at the lowest area in the groin, is a stretch of skin. That's the "taint". Its scientific name is the "perineum".
The way I heard it, it got that nickname because, being between the two other places, "t'aint one nor t'other".
So if a man gets his johnson whacked off, and he wants a hole so he can pretend to have woman-sex, they can cut a hole into the perineum (taint) and fashion a sort of vagina. Of course, the body sees it as a wound and tries to heal it shut, so it has to be forced open daily.
You're right, that's TMI.