Just one single abattoir can slaughter 2000 cows every day and they are doing it in a humane fashion. A major industrial power like Nazi Germany would have no problem at all with killing 2000 frightened, confused, unarmed civilians in a day. That's 730,000 in year, nearly 1.5 million in two years, in a single camp. The Nazis had six dedicated extermination camps.
Denialists think that murdering six million people is implausibly high. I think it is a miracle that it was only six million. If the Nazis weren't fighting a war at the same time it could have been sixty million, easy peasy.
(Fact: most of the six million, plus another eleven million non-Jews killed by the Nazis, were not gassed in the extermination camps, but shot, starved, worked to death, beaten to death, hanged or otherwise killed.)
