Have you tried LAT training yet. I thought I would never get anywhere with Raina's DA but I've been doing the "Look at that" training and it has been working. It takes a while with an older dog - she is 5 years old now and I just started the LAT in the past year. Whoever told you that tension goes down the leash is right. Your dog can tell if you tense up and it thinks there is a reason to get tough. That was the hardest part for me-remembering not to tense up but treat the situation as a training tool. When I see another dog I put her in a sit and get her eye attention - when she is calm and in a sit she gets treats until the dog passes. I was really pleased a few days ago when all my hard work paid off - a stranger was in my yard letting their dog relieve themself and I put Raina in a sit on the corner. The man yelled at me to control my dog - she was not barking just sitting. I yelled back at the man and she stood up to see if she needed to protect me but she immediately calmed when I did. I told the man to move out of my yard so I could take my calm dog home. This takes a while and you have to remember to remain calm. There are others on this forum that have used this technique and could probably explain it better.
Snake Vom Eselspfad RN CGC (AKA Raina) 3/5/08
Pyrate CGC 4/1/03-5/16/12 RIP
Too many to list waiting at the bridge but remembering them all