your approach sounds like a good one. If that does not work, I'd try lighter fluid to disolve the paper, glue, or "goo be gone" an orange gel similar product.
I'd bear in mind that the LP is a dead loss at this point, so try things in their mildest form first - soapy warm water as you propose. Good luck, let us know how it goes.
I'd bear in mind that the LP is a dead loss at this point, so try things in their mildest form first - soapy warm water as you propose. Good luck, let us know how it goes.