I think that you are going to be disappointed in the stun guns performance take a look at You Tube. It why no Cops carry them. You have to maintain contact to get compliance it is not a Taser. Every street dog that is loose has had rocks thrown at them. I have walked my dog over a mile every day and the good old "bend over and throw motion" works almost every time. Only about 10 %of the time have I had to actually had to throw on.
I hope you are correct, but in the last week alone, and for the first time, I had two dogs attack, or almost attack my young pup. One was a German Shepherd guard dog that got out. It was a very close call and throwing a rock did not deter him. Fortunately, no harm came to my dog because their two human guards were able to regain control of the GS. Had they not been there things could have gotten really bloody.
Two days later is when my dog got attacked, and I didn't even see it coming. It was not a street dog, but a dog that escaped a fenced yard.
We see street dogs all the time, and they never get close. And you're right: the average street dog will run from a thrown rock, or just a throwing motion. But that is not what happened to us recently, and now with a negative experience, I want to be better prepared.
Between a shock---we aren't talking humans, we are talking animals---and a club, in both situations I stood a better chance of protecting my dog and myself.
Stun guns are handheld items a tad larger than a cell phone. You gotta get really close. The one I bought, and there are many more like it, is 19" long, long enough to not have to be so close to deploy. And if the visual crackling spark doesn't work, if the shock pain poke hard doesn't work, I'll bash the dog with the club. I know that will work.