You are missing the whole point. A Koser butcher is required by their religion to cause no suffering. If they believed paralyzing/electrocuting an animal before it was butchered was MORE in keeping with their doctrine, they would DO IT.
Personally, as a non-Jewish person, who has raised, killed and processed my own meat, I don't see how torturing an animal, by electric shock, before you kill it is a good thing. It just makes PETA people feel good.
Maybe that is a fair point
From the Jewish perspective (I’m talking Orthodox, for convention) it’s not about the pain-or-not, it’s about our belief of how G-d commanded Jews to slaughter. If He said, “Tickle the animal to death” then that would be the method until today.
As it happens, when one searches for deeper meaning behind the commandments, it seems that kosher slaughter is the most painless way. But it is not not primary reason for slaughtering in this method.
Likewise the false belief that Jews are prohibited from pork because of trichinosis. False. It is all based on our belief or what G-d commands. “Don’t eat from these animals....[including pig.] (I’m saying our belief, less non-Jews wish to argue about correctness of beliefs.)
But so far we just seem to have ethical-animal-treating atheists on the thread. Well the body of evidence seems to indicate that modern stunning techniques in conventional slaughter houses are no less painful that kosher slaughter.