Everything I've read about the care and maintenance of hair sporrans say that you treat them the same way as your own hair (with the exception of not getting the adhesive or bag wet - though if your hair is being held on with glue, you probably shouldn't get it wet).

Because of this, I'd think you could probably use a straightener on the LOW setting to carefully work them out. I wouldn't go any higher than low, though, because too much heat will damage the hair.*

You might also try giving it a careful shampoo and conditioning, followed by a good combing.

* I'd get a second opinion on this before actually trying it!