A denier pic comparing American gas chamber doors to the ones in Auschwitz

In this widely circulated pic, holocaust deniers try to make people aware of the existence of gas chambers for executing people in the United States and use them as proof of how "complicated" gassing with Zyklon-B really is, and how the lack of such doors in Auschwitz is proof no homicidal gassings could have possibly taken place there. Both Fred Leuchter and Robert Faurisson are pretty hysteric regarding this. Already, part of this "infographic" is a flat-out LIE obviously intended to only fool the clueless, because the door pictured on the bottom right is NOT the homicidal gas chamber door of Auschwitz's Krematorium I, and isn't even claimed as such by any historian or reputable camp authority. What you are seeing instead, is the 2nd of two wooden doors in Krema I's enlarged gas chamber today, a building that underwent renovation in 1943 after homicidal gassings had been moved to Birkenau, and which was subsequently used as an air-raid shelter, as is stated in the sign in front of the building brought up to explain this to the million or so tourists that visit it each year (imgur.com/duS3xZA). I have explained what the 1st wooden door is previously (imgur.com/1bm1yrw). This 2nd one (the two are distinguishable from one another in that this one does not have a missing wooden panel in the upper half) leads into a small vestibule built in 1944 in front of the other exit of Krema I (you can see the far sturdier metal door behind it). Now let's look at the other two doors in the infographic's bottom left. The denier narrative goes, that these doors were claimed to be homicidal gas chamber doors (note the hemispheric metal grid over the peep-hole on one of the left one's sides), but in reality are innocent delousing chamber doors, as deniers do not believe in homicidal gassing, but do accept Zyklon-B's historical use for fumigation and delousing. Even if the two doors on the bottom left are "just" doors of delousing chambers, holocaust deniers still have a problem: Considering these doors are made out of wood, and therefore "flimsy", and therefore Zyklon-B gas leaking out, the deniers would have to abandon their argument about Zyklon-B being used for delousing as well, because using their same, frequently toted "leaking is lethal" argument they use to discredit homicidal gassing, the case can be made that even the delousing chambers would kill everyone around them due to gas leakage. And keep in mind the delousing chambers were located far closer to the (women's) inmate barracks than the homicidal gas chambers, as shown on the Birkenau camp map here: imgur.com/wdxcRbF. Make up your minds, deniers - either these doors saw historic use involving Zyklon-B, or you need to abandon your stance on delousing as well. Krematorium II and III, located underground, had a ventilation system proven both by testimony and documents (blueprints) here: (imgur.com/cXSdJkz), here (imgur.com/17mmlGM), here (imgur.com/KxRpFZ5), and here (imgur.com/mBd6lps), while the other gas chambers were at ground-level and therefore easier to ventilate simply by opening the doors and chimney vents. We know from chemistry that Zyklon-B is lighter than air, and by venting out into the open air it rapidly loses its lethality[1]. This is the reason why the aforementioned American gas chambers also vented the gas via exhaust tubing into the open. Now then, deniers will have to make up their minds whether Zyklon-B that escapes from high concentrations in a room and mixes with the air of the surroundings continues to be lethal (in which case no delousing could have taken place either using said flimsy doors), OR is only lethal within the chamber and loses its lethality when escaping the chamber, in which case the hermetically sealed American gas chamber doors are NOT a necessity but rather merely an excessive security measure that complied with stringent American safety standards. Long story short: American gas chamber doors do NOT debunk the doors used for the Auschwitz gas chambers, which are also NOT the wooden doors still existing inside Krema I today. But we still have one more argument from deniers, and that is about how easily these doors (they still use the picture of the wooden ones) could have been broken down by those trapped inside. I address this here: imgur.com/q9Qrcf3 Source: [1]: https://www.atsdr.cdc.gov/mhmi/mmg8.pdf