Wash and rinse with an old paint brush and dish soap in a wash tub type sink. Sometimes I spray down with Simple Green (or sometimes Mean Green). Let air dry standing on end in a tube for a few days (usually takes me that long before I am ready to mount back into the machine).

Have never removed anything other than the batteries (which make sure you do before getting the board(s) wet.

Doing the soap and water for over 25 years (the Simple/Mean Green part I started a few years ago and only on the really nasty boards). The 'dust' just with soap and water.