Be sure you make it really easy to get the stuff out of the Kong until he gets the hang of it. I would smear some peanutbutter on the outsite around the opening at the bottom and a little on the inside until he figures out the good stuff is inside the Kong.

If you are going to give him left overs be sure to adjust his dog food accordly you don't want to end up with an overweight dog. I use the Kong brand cookies because they last a long time and keep my dogs intrested for hours. You need to get your dog intrested in the Kong before you start making the food diffcult to get out.