Thats a hard one since you couldnt use acatone on her body. I mean Ive used it for particularly difficult marks very sparingly and carefully but Ive never had a pearlized pony and Id be leary if I did.
For the hair u might want to see if maybe some goo gone might help. Just be careful.
My MiL removes label residue from her prescription bottles (dont ask) by filling them with water and microwaving them for a bit.
I dont think a microwave would be kind to your pony but perhaps a soak in a hot water or even a bit of a boil may work.
Let me know what works, Id like to know.