The best way to keep him occupied with it for a while is to put actually peanut butter in it. It may take him a while to get that last bit out, but I bet (unless you got a very big kong and have a teeny dog) he'll eventually get that last bit out! I know one dog who loves to chase his, like a ball when thrown, except it bounces in unpredictable ways, or to play tug-of-war with it - hint: you cannot hope to keep a grip on a smooth and slimy kong - grip it with your thumb inside, and a finger outside, or vice versa - it's your only hope!