Your chin's favourite chew toys

What are your chin's favourite things to chew on?

I've been trying out different chew toys and materials with my girl, and while she'll chew on most anything, she definitely has her preferences when she's given many different choices. Apple sticks are a favourite, of course. Though she only seems to like apple wood in stick form. She mostly ignores the slices (she'll nibble them a little when they're on hanging toys, but that's about it). She also goes wild for pumice stone and those...

Your chin's favourite chew toys