Pulled out of an image entry and put here because I thought a separate entry might be more useful if anyone wanted to try it. Also, reorganized to make slightly more sense.
You can, without too much difficulty, use Amazing Skins by V3Digitimes on the Genesis 2 Male genitalia (and, I assume, the Genesis male genitalia, as long as it has a full Michael 5/Genesis Male Genitalia texture -- not sure how this would work with an M4 SkinGenitalia section). It's the process I used in both Joe Patrice Mahalo in the hot tub pergola (take 2) and in Still rockin' (those are both Mature restricted images, for obvious reasons).
OVERVIEW: One key to this process is that Amazing Skins is a shader BUT it uses Materials-like presets, and it's explicitly designed to leave underlying textures where the