Stuff it, chuck it. Your dog will love it!
My dog had the large puppy version of this and I normally put mince in it and freeze it. I give it to him frozen before leaving him for work. It keeps him entertained and mind stimulated while I'm away. I recommend frozen because he finished it very quickly if not. I also recommend XXL for large dog even if they recommend L-XL only because there's not much and you can fit in it and the more you can fit the longer they will be entertained. Very happy with it. KONG is the best brand.