Hi again,
Have you tried trimming his "private region" with small scissors so that the hair isn't in the way? I have to do this on a regular basis with my 'girls.' I've always had to trim my dogs in their anal & genital regions regardless of breed & their regular coat length (Beagle all the way to Yorkie). They get used to it quickly. I've yet to do any major damage :D
Oh, with my Yorkie, I'd trim her belly area, but leave the sides long like a curtain. Easier to clean, but no one knew :D
Um, the idea of his self cleaning this area and then licking your hand a little later on, is a little off-putting

:P I understand the concept of saliva & the 20 minute changeover, but still.... ick.
Hope this helps.
toodles