i guess it all depends on how furry your b-hole is. Me, I've got fine hair - no pun intended - so not much to work with. twice a week keeps it smooth and easy-to-clean.
I would have to say the same thing about a shaved nani. even though this thread is about the boys, a shaved nani not only is HOT, but it's clear sailing, so to speak, to all the pleasure points of interest!