I've had pretty good luck with the bark collars for the consistent barking dogs. Trick is the same as using training collar to trash break or whatever...to take battery out and let dog wear it a few days before actually letting it do work. Dogs figure out collars VERY fast and they'll quickly learn to not bark when wearing, and start right to raising hell the minute you take it off.
Agree 100%, they r some fast learners. Unfortunately i learned that to late. If i walk outside with a collar, the barkers shut up, i can put it on them and they wont say a peep. I take it off and put it up and they go back to barking. Now they have learned the rattle of the bb gun, but doesnt help if i have to rattle it everytime just to shut them up. If they wouldnt work as a team and chew the collars off each other, id keep a bark collar on them all the time, but they seem to work together to chew them off then chew it up beyond repair