Whats the inside of a kangaroo pouch like?

Inside a Kangaroo pouch is just like skin- there's no fur inside- and it has teats for the joey to suckle- there can be two in there a quite grown one and a small one (and the milks are different in the two teats!! I think that's incredible!) it is quite icky because obviously it doesn't get cleaned out and the tiny joeys have to "go" somewhere right (I'm talking about the really little ones that don't have their fur yet...and don't have their eyes open yet). I tried to find a picture online- but I couldn't find what I was looking for.