Well, I wouldn't use one again (ultrasonic) for anything in the world. Someone in my family bought one for Muffin. I didn't want to put it on her, but I did just to see what happened. Well, she didn't bark. She did start shaking. It scared her to death. I immediately took it off of her and threw it away to make sure it never adorned her neck again.
I much preferred to hear my little live-wire bark.
