The duck seems like a tough material but time will tell. As for the "chew resistant rope", I am not too sure about that. I received my package late Sunday night and opened it today to give it to my dog. Within about 30 minutes of unboxing the product, the rope was bitten into two and thrown. And I am not even talking about a large sized dog. She is a very medium-sized Indie female.
I'd suggest changing the rope description on the product in order to avoid misleading customers.