I try not to rub the bum with a rag or anything. I usually hold their little butts under running warm water and use my hands to wash a bit and pat just a few times and let her/him air dry....Does sound gross but I do imagine thier lil butts get raw as ours do. My poor son uses vaseline...Hey maybe do that....I doubt that would be harmful if he licks it....maybe look that up if vaseline is toxic in any way I dont think so though...Lots of peeps use it as lip balm. hmmmm maybe that would soothe his lil bootie!