I'm no vet but I would think that letting him have a warm bath and then letting him wiggle through a towel after it is over would be the best thing. I use wipeout and it's designed to be reasonably gentle. Let him soak in warm (85-88 degree) water for a bit, then let him squirm through a clean towel. Repeat the procedure again with a fresh towel. Probably don't need to let him sit in the water more than a couple minutes, and it should only be about as deep as he is wide (ie don't make him swim to stay afloat).
FYI all those shedding aids are garbage. Throw em out.
JonV