As an afterthought,

A wise 'Catter should try to identify the species of any animal product they might consider using. Several of the box turtles on the eastern seaboard (U.S.) are endangered species and you might land in trouble for just having their remains.

The Marine Mammal Protection Act covers all products unless you have a special permit (even if it did wash up dead on the beach!)

I know sea turtles are also covered although I can't cite the law involved. I believe it might be the Endangered Species Act.

In any case, C.Y.A.!