If it comes to training your Papillon, for show, or any other activities, you need a good snack, and only tiny bits and pieces of it.
Try "String Cheese Sticks" (low-moisture, part-skim mozzarella cheese).
Cut a small piece of it of and put it in your pocket. when you train, let him lick the cheese most of the time, while you keep a strong grip on it!! Then, every once in a while let him bite a small piece off, or pinch off a piece for him.
Those cheese sticks last in your fridge a long time, so you will always have some of it available for your training.