A prisoner "Sonderkommando" (Special Detachment) effected in the processes of extermination; they encouraged the Jews to undress without a hint of what was about to happen. They accompanied them into the gas chambers outfitted to appear as shower rooms (with nonworking water nozzles, and tile walls); and remained with the victims until just before the chamber door closed. To psychologically maintain the "calming effect" of the delousing deception, an SS man stood at the door until the end. The "Sonderkommando" talked to the victims about life in the camp to pacify the suspicious ones, and hurried them inside; to that effect, they also assisted the aged and the very young in undressing.