I would put it on paper towels until you are sure that the eyes are not irritated or even infected. If substrate is sticking to the eyes, they could be oozing. Walnut is not a good substrate for anything, IMO, and I really don't like sand either.

When I kept an American legless, I kept it on organic garden soil with a bit of sand mixed in, and threw a thin layer of bark over it, then provided lots of secure hides. You have to make sure the soil is organic so that it doesn't contain fertilizers and pesticides.