Harper, the beauty of using a good haltie is that you have full control of the head. When he sees another dog and before he reacts lure the head gently towards your hip. His head is his balance. I have taken some pretty narly shelter dogs and used a haltie. The non believers ran out and bought halties.
. I just showed them how to use it and everyone that I know of is very happy with the results.
I also have a tracking leash. I use the leash as normal (clipping to the collar) but use the static ring in the middle with the end clip. I then swing the leash across the shoulders and this also works great as it prevents the dog from moving forward..or in other words it restricts his movement to lunge. It is hard to explain but anyone that uses a tracking leash can show you what I mean.