If he's going into shed, sometimes they do get more skiddish. Mine won't even peek their heads out of the hides like normal. I would just let him chill in his hide until after he sheds. Some snakes are just really feisty. I know I have a few of those

If he actually does have aspen in his mouth and is having a hard time getting it out, you can hold his head, face his nose down (so as not to actually get any water down his throat) and gently rinse away any debris.

If he has excretement like peanut butter, like Steve said, that's not a good sign at all.