A good bark collar works very well for many dogs. They are far from useless. If you're at the point where you're this frustrated with your dog, and you refuse to rehome her, then please just get a bark collar and be done with it. Seperate your dogs if you're afraid of them chewing off the collars.
It really can't be more simple that that. Buy collar, put collar on dog, that's it. Very simple.
I prefer the Tritronics bark collar. Spending a little more and getting a good one will make all the difference. Cheap ones often times are useless.