Yes, you can clean the skin and poop and everything now.Fun stuff, that!
As for the stuck skin...first, just try to gently rub your fingers down his tail and see if you can get it to roll off. If it's stubborn, don't force it. Place him in a small tub with about 1/4" to 1/2" of water that is just barely warm to the touch. Let him swim/soak in that for a little while, and see if that stuck skin doesn't just slide right off.![]()
After that, I'd give him another day or two to settle down and then see if he is interested in eating.
Good luck with him!! Let us know how it goes.