It kind of seems like it just depends on personal preference?
I know this question may seem a bit graphic, but how can you tell if there is really anything necessary to clean?
During the summer she usually gets hosed all over including in between her legs.
During the colder months when it is too cold to hose, I usually rarely clean her underside even with just water, I just continue as usual. How often would be a good "underside cleaning" schedule? Maybe once a week for these colder months, or..?
Also, while i'm at it, do you take any special precautions to clean the nose?