Any good cleaner will work with a good soaping & hosing down !! But choose one with bleach or add some bleach to (couple of TBSP) disinfect and help brighten the white !! If there are stains that persist use a Teflon scrubby gently !! WD40 the axle joint and a little oil,, cooking oil will work,, on the rubber tires then wipe all excess off !! Then let all dry !!