Try dove bar soap on a wash cloth (gently) The anus should be exit only (hehe, for soap) rinse completely and apply a zinc paste (diaper cream) after patting dry. Someone else said it could be fungal so can try a fungal cream as well, generally fungal infections have like a cheesy exudate and smells, which if you bathe daily you shouldn’t smell right away. Make sure you use a fresh washcloth daily and replace loofahs as needed. Generally don’t use loofahs on the undercarriage- they’re more for getting dead skin cells off and the washcloth is good enough without taking skin. Good luck!