I was wondering when this would come up. For those that wash their belts, I have a question. Do you wash normal (i.e. non martial arts) belts?
Most of my belts are leather. On occasion I have taken some saddle soap to them, but they don't get dirty enough to need this very often.
Then again, I am rarely rolling on the floor when wearing leather belts. Nor do I usually sweat through my everyday clothes enough to worry about salt stains on my leather belts.