A "p" sound, a "u" sound, and a "t" sound ("ch" is attested as a changed "t" sound; think of how "t" changes to "sh" in going from president to presidential), in that order, referring to female genitalia.
Yeah, it seems a stretch, to go from female genitalia to male. I don't know of any well-attested examples of that actually happening, but I wouldn't be *too* surprised. In 103, everything except this one seems reasonable to me.
Is it rigorous? No. It's a best guess.