Barkbusters use this method you can use water bombs as well it can also stop a dog from lunging at another dog when out on walks, its a way of bringing the dogs attention back on to you, you drop the bomb on the floor in front of your dog the noise and the droplets of water should stop his bad behaviour so that you can reinforce that desired behaviour. I will say this though some people on this sight won't like this method as it's not what they call positive reinforcement training, I'm glad that it works for you as I know that pos reinforcement does not always work with a lot of dogs but as with any training of this type be very careful you can easily get the wrong outcome if you do something wrong. Good luck with the training :-)