Whatever you use your buns will scratch and chew but it doesn't matter as long as you are feeding them properly. There is too much worry about the odd bits getting nibbled and yet we are happy enough to give them cardboard to chew on which can't be brilliant for them either if you follow all logic.
Read the labels on pet bedding, toys etc....to be used under supervision...or to be accurate...we are happy to sell you anything you like, but at your own risk.
For the record, mine have old towels and a pet blanket.