Go to the dog pound. Look at which anti-bark high pitch device they are using. And DON'T buy that one. Dog pounds are so loud, they can't possibly work that well.
The lady at the pound did tell me that it only releases the high pitch once the noise reaches a certain level for a certain amount of time. Then half the dogs shut up for about 5 seconds before barking again. Could be they have theirs turned way down. So if you can (if it's on the package) check out how loud it has to be for it to 'chirp' as well as how long the dogs have to be barking to activate it. And how close the dogs have to be to the device to set it off.
I wish they made one that would scream bloody murder each time a dog takes a crap in my yard. And loud enough to hurt the ears of the owner who allows their leashed dog to do it.