The Germans invented the captive bolt pistol which was invented in 1903 by Hugo Heiss, the former director of a slaughterhouse in Straubing, Germany. It is currently used worldwide for the mass slaughter of cattle, sheep, deer. A captive bolt pistol is intended to deliver a single, powerful strike to the forehead of an animal in order to quickly induce unconsciousness. Depending on the variation and usage, the bolt may or may not penetrate the skull and cause direct damage to the brain. They would be lethal to humans. This is the method of mass killing of livestock today in Germany and worldwide. Millions of animals today are killed this way. The Germans also guillotined more people than the French during their revolution; more messy than bolt guns. Hanging was a common method for partisans as well as shooting. They also built carcass shredders which would have confettied a corpse in milliseconds, whole trainloads in seconds even if thrown in alive. These would have been the methods. Gas was reserved to kill the typhus vectors of lice, fleas, mites and ticks.
It was claimed that Jews were electrocuted at Belzec and burned on white hot floors. They also climbed trees that were cut down. See no reason why they would not be microwaved if extermination was the aim. Of course it was not, people were necessary for the war effort.
