KONG Classic Stuffable Dog Toy

I have used this toy for training my dog since she was a pup. I always try to have the rubber toys that she plays with the same color, red. After she associated a red toy with play time, I can use any red toy during our training sessions to get her back on focus. I have the X-Small toys so I can keep one in my pocket. If she loses interest in what we are doing, I just let her see it. That gives me another 5 minutes of her attention so we can finish the training. To keep them clean, I do not put food or treats inside them. I do not let her chew on them. She has other red toys that she plays with that she can chew on.