Well firstly, don't stress him too much. I would think that warm soaks and massaging can be a first line assistance for him. It could be a piece of substrate. It will help to raise your humidity percentage too. They are pretty efficient at getting things out of their systems that don't belong there. Keep a close eye on him and i think you will be okay.
Hmm, he's on paper towel so I don't see what he could've eaten to get stuck in him.