I ordered an Anti-bark electronic dog trainer, Bark Trainer model A171
by Brighter Image. This simply doesnt work as far as I see - there is
little relation between the dog barking and the ultrasonic sound being
emmited.

I've tried various sensitivity settings but none appear to improve it.
I would say it gets triggered every 10th bark or less, and half the
time it gets triggered when the dog is not barking, such as
scratching, or what appears nothing at all. And on occasions when it
has been triggered the dog wonders what the noice is, but then
continues to bark and the ultrasonic sound has little effect.

Not a cheap device, so I was wondering whether others have had any
success with this?

In addition, this one takes three wris****ch-size batteries which only
last little more than 1 month according to the instructions. So it's
not cheap to replace those batteries. I'd of thought a single AAA
battery would of made more sense given that the device isn't exactly
small.