I have owned quite a few geldings over the years. One
advantage to having an ex racehorse gelding is that
they frequently (all of mine) have been trained to
drop down for post race pee in the cup, so it is easy
to clean their sheaths. I rinse my boys' privates with
each bath/ hosing.
With one of my two who did not just let down (my last
guy would drop if you rubeed his belly), I could just
insert my arm with a wet cloth and clean. I originally
would have him sedated, but even when he was sedated
enough that he could barely stand, he would still try
and nail me. I was a pony clubber, so I had to find a
way (privates get checked at inspection to make sure
you are properly carrying for the horse). He got crazy
beans, and seemed to appreciate my help, he just
didn't want to let down.
The other guy had to be sedated, but I didn't work
much with him. We just did his sheath after his dental.