Yeah, because you were not born in Europe in the early 20th century.
I was born during the German occupation of Poland, which, if anything it should be worse. To separate Jews from Catholics, Germans should be super diligent in labeling me as Catholic but they didn't.
Yeah gas chambers with wooden doors... makes total sense..
Before we discuss wooden doors, an honest approach to the Holocaust must include (1) the number of people who were brought by trains to Auschwitz, Treblinka, and similar places and (2) the real purpose.
Next (3) how many of them survived, and (4) what happened to those who didn't. That's where I would start if I could talk to one of the "deniers". I would allow 10 minutes to convince me that Auschwitz is just a hologram or at least a theatrical setup.