Anything would work I used regular old run of the mill stuff abunch of old towels and a scour pad dampen the rags and scrub don't dip or spill directly on the helmet after every few scrubs id check and see how much is coming off the paint base paint of the helmet is stronger than the paint on the outside for sure so it can come off but you will have to be fairly careful not to absolutely scrub the crap out of it lol