Breast milk! lol it's one of my fix-all's, just rub some expressed milk under there lol and wash often, they get all sweaty, stinky baby under their chubby lil double chins 😂 if not breastfeeding, try coconut oil! That's my other cure all 😉 works great for diaper rash (can't bring myself to rub boob milk into my daughter's ass hahahhaa just too weird) and cradle cap!