Well, firstly I'd set up an arrangement of baby gates so that he couldn't get out of the door.
Harry isn't 'treat orientated' at all, but he DOES love the squeaker inside the squeaky toys. I keep one of those teensy Kong Air squeaky tennis balls about my person and do a short, hard, very sharp squuuueeeeak on it along with 'come' - and he always does...
He probably thinks I've got a mouse in my pocket...
