re: Anybody used a bark collar on their dog? Do they work?

Yes tritronics makes good stuff. I think the effectiveness depends on the dog, I had a beagle that would run the batteries down in her bark collar in a day or so. I had another beagle that you could put an extra plain collar on him and he would stop barking. I think most dogs fall into the second category, and if so the silence can be heaven on earth. Bark collars are definitely worth the money.