Just to clarify, that is not remotely what I think. IMO, except in very specific circumstances, even one shock is too much. You do acknowledge that in many cases the dog will never need to be shocked, and if that is the case (and I do believe it is possible for almost every dog, with the right training) then why not save the money on the fence? You can get 50 boundary flags for less than $10, train the dog to the boundary as you would with the fence, and not have to use electric shock on your dog or risk the potential fallout that comes along with it.Unlike what many think about the invisible fence you don't have to continually shock your dog to the them to stay in the yard.
I would suggest putting them on your neck for a more accurate comparison.I have held them in my hands, put them on my legs and arms, and have survived the shock at different levels. My husband has also done this.