there were a few things.

because the camps where near wooded areas, they had to bug bomb some buildings from time to time. the "smell of burning bodies" was just the killing of bugs

Russian POWs had the experiments done to them. pretty graphic too. removing limbs and attaching them to other people. testing pain tolerance with surgeries to see how much a person can take. granted we did get the tech of organ transplants and reattaching limbs because of this.

some of these doubters of the delousing chambers also don't understand Russia annexed Auschwitz. you can find stories of Jews being reunited with their American savior, which never happened. guy wrote a book on his survival of the death camp by "moon walking" away from the gas chamber. there is so much money made from the victim lie, they won't let a piece go because it would all go.