I use a puzzle ball, kongs with treats, plastic Bottles without lid and ring, icecream containers with lid on and treats in it for my American Staffy who is a puppy until he turns 1 in october, he loves to detroy things. Vicks does wonderful things if you dont want him eating something, he doesnt go near outdoor setting as it is partly covered. Our puppy loves apple, peanut butter, vegemite spread, banana, liver treats and bits of pieces.
Good luck, only thing with boxes you have to clean it up!