Iirc, that was declared as cruel and inhumane by animal rights activists back in the late 80-90's. It's partly why Foam and or monoxide poisoning was utilised by Big Farma in an effort to produce a more 'humane ' way of mass termination. Activists are never ever happy - appease them once and it becomes a continual ongoing saga. I recall activists 20 or more yrs ago unhappy at cattle getting the bolt into the brain as 'barbaric' bc the animal could sense what was about to occur, ffs.