Leave bits of dirt and scuffing, it makes it better. So unless it's mud, prickles, or paint I wouldn't worry about it. If it's necessary, try a warm cloth and hand clean the areas that need it. If it's completely soiled and disgusting, washing machine on delicate (minimal soap) and hang dry. Make sure everything is removed, especially foam layers or plating.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē