We have a set of those. They do work although we have one dog who is immune to their effects. We got a set of 4 collars trying to teach our Muttley Crew to stay in the yard and not chase Amish buggies. It worked for three of them but the forth, our 13 year old Border Collie would ignore any 'cue' you gave her. We tried turning up the power and she would still ignore it. Finally we turned it up to maximum. She would jump in the air and keep on with whatever she was chasing after. She had been badly abused before I found her as a stray and adopted her. I figure that she was thinking, well, that's nothing compared with when I was a pup and beaten' We took the collar off of her and never used it again.
As for using a hot wire, One of our dogs will test it with his whiskers to see if it is hot or not. The same dog will take a running start and blow right through it if he is so motivated. He does respond to the training collar though as do the other two dogs. I've found that the best determent in general has been a hot wire. Our Cattle Dog has stuck his nose on it a couple of times. The most effective experience was the day he lifted a leg and peed against it. He never went near that fence after that and it was ages before we could get him to go in the front yard.