A scratch probably isn't going to cause any problems. If you suspect infection then soak him in a bath of 1 parts Betadine and 10 parts warm water. This will disinfect the wound. Do NOT use Neosporin as it will make things worse.

I would make a hand towel amp with warm water, then let the BP slither through the towel while you apply some pressure. this should help get most of the stuck shed off. I would maintain the humidity at 60%-75% until all of the stuck shed is gone.