how do you clean down there properly?

hi, this is an extremely uncomfortable topic for me and i feel really embarassed but i have ocd and i dont know how normal people clean their butt.
like, how "deep" are you supposed to wipe? i dont feel clean if i only wipe the outside, but if i wipe the inner part as well, i keep triggering the urge to poop more even if im finished. (so i usually just end up taking a shower.)

also, how do you wash it in the shower? do you have to clean the inside of the anus or just the outside? because again, i feel like i still stay dirty if i only wash the outside, but i dont know if washing the inside is something other people do because it seems really disgusting.

im so sorry again for asking this.. i got so deep into my ocd that i dont know what are actually compulsions and what arent and how im actually supposed to do it..