Perfect for use as a training tool, use a pull-and-RELEASE action, so that your pull turns the dog from the direction he's going, towards you. Immediately, as he is redirected, release the pull, so the lead is slack. We have found that this tool works best with a 2' or 4' lead.

Use vocal praise when the dog looks at you with slack in the lead, reinforced if you wish, with a treat. Use a very small piece of some high-value food like cheese, hot dog, freeze-dried liver, whatever he loves, as long as its small. Your dog pulls you, you pull to redirect the dog, releasing the tension as soon as the dog has turned towards you, at which point you make sure he knows you think that it's the greatest thing he's ever done. Be consistent in the redirect and use lots of praise.

The No-Pull harness does not keep the dog from pulling. It helps you convey that pulling is much less rewarding than not pulling. You should see some improvement pretty quickly. The time it takes to change a behavior greatly depends on how consistent you are. Well-exercised dogs learn faster than dogs with too much pent-up energy, but all dogs can learn to walk politely.

For very reactive dogs, try practicing in the house where there are fewer distractions. Also, changing direction frequently keeps the dog thinking about you. Praise him for keeping up.