Give him a brick to chew on.
ACTUALLY, he does "play" with a cinder block that's in the backyard. This dog will drag the ****er around... no kidding!
The peanut butter in the Kong works, only for a few minutes. I fill the thing with small dog treats, maybe some cereal like Peanut Butter Cap N' Crunch, some of his dog food, peanut butter or cheese, and then have a dog bone cookie sticking out of the other end.... he's done with it in 10 minutes, and then wants me to throw the damn thing!
Well, when I get paid next week, we'll be heading to the PetSMart to try something else more durable. Like a cat.