I think it depends on the dog. I used a front-clip harness when Juno was younger, and while it gave me more control than when she was just on a buckle collar... she could still pull and she was still able to throw her weight into it if she wanted to get to something. So, it helped a little but wasn't magical and didn't make a huge difference. Gentle Leader I don't find deters much either, I used to use it on Juno and now I put it on Happy when we go to pet stores. Again, gives much more control, but doesn't stop my guys from hitting the end of the leash. And both of them shake their head around a little bit every time they do. It kind of adds a new set of annoyances to walks, honestly. Juno actually does really well on plain old harnesses that clip on the back, believe it or not. I know it's supposed to encourage the opposite but yeah not with her. She can still be naughty when the mood strikes though. Leash wraps work pretty well, they make Juno really sad though. Dear God I feel like I have used every single contraption out there.