You say your dog won't chew on a kong? Then my question is what are you filling it with? Peanut butter is generally my first suggestion, but there are dogs who don't go crazy for peanut butter (mine prefer cheese). So try something else - cream cheese, yogurt, braunschweiger if you mean serious business! You can also freeze it to make it more challenging to empty. Ideally, your dog will expend so much energy getting the goodies out of the toy that afterwards he'll just take a nap.
You say your dog won't use a kong wobbler? Then show him how! Put some really good smelling treats in - pieces of freeze dried liver or sausage and sit it on the floor. Give him a chance to investigate, if he touches it, praise him! He may need a little help at first, so you may need to tip it over a few times so that he can see how it works. Be a coach - show him the ropes! Once he gets the hang of it, you'll probably be able to use just a basic kibble instead of something higher value.
Give your dog a food puzzle when you leave the house so that he has a reason to be happy that you're leaving, as opposed to being sad and bored. Believe me, it's in your best interest to give your dog something to do while you're away, and a food puzzle is usually a good choice.
Please keep in mind that it's not a good idea to leave a high value treat like a filled kong out with multiple dogs while you're away. I use these toys as a consolation prize for the times when one dog gets to go with me, and the other dog has to stay behind - another thing that you should be in the habit of doing, but that's another blog post!
