Yeah, I've tried both that and using wood blocks that I can shove food inside. For a while Grizz was really into chewing the Aspen bedding in their litter box... but that is as close as I've gotten to success.
Mine really like it when I make tiny sandwiches out of the little square wood chews that you can get at Petco. You put a thin layer of peanut butter between two or more of the chews and then freeze them.
They dont need to chew things at all, its one of those internet rat myths . The brux when they are content and restin and this files there teeth to a nice point. Also eating hard food helps too. You only have to worry about keeping there teeth short if the teeth are uneven or dont meet.