I know that BarkOff works because I have one.
The difference in my household has been dramatic. Because of the complaints of my neighbors I was frantic every time Suzy would start barking at squirrels she saw in tree, neighborhood kids or other dogs. After I got my BarkOff It only took about a week for her to learn when I reached for the BarkOff it was time to stop barking.
I am a lot less stressed now and am no longer worried about Suzy getting into trouble for barking.
It is great product and has made a huge difference to the whole family and probably the neighbors too!