Then I stand corrected. Who was employed at Auschwitz then? (I am not currently in the presence of my library.)
This depended on the phase. In the 'Bunkers' phase the SS seem to have done all the guarding and cajoling during the actual gassing, then brought in the Sonderkommandos afterwards to clean up. Also in this phase, SS doctors did not usually carry out the actual selections but were merely present as per regulations for executions.
With the new crematoria beginning in March 1943, this began a new phase. SS doctors began to carry out the actual selections on a systematic basis, and the Sonderkommandos were brought in to the process more than hitherto. I think their involvement increased over time.
The changeover made sense because the Bunkers were not located in a closed complex and had to be sealed off by a substantial guard force. With the new crematoria, guards were still necessary to secure the transport on arrival (and would have been necessary no matter what you were doing). Up to May 1944 selections took place on the old ramp, outside the camp, and then the condemned were escorted into the camp on foot and by truck guarded by SS men. From March 1943 the condemned were then taken into the crematoria zone which was behind barbed wire.
Once inside the enclosed zone there was less and less need for heavy security, because the condemned were more and more trapped. Once inside the undressing room, then there was virtually no way out and deception was going to be more effective than brute force.
From May 1944, selections took place on the new ramp inside the camp, i.e. the prisoners needed much less guarding because the barbed wire fences and guard towers did that for the SS. This was also when prisoners were assigned to help the new arrivals. These prisoners were not from the Sonderkommandos but from the Kanadakommando which processed property.
There were thus at least three different phases and three different but evolving sets of procedures. The first phase affected fewer than 200,000 victims, the second phase also about 200,000 victims, and the final phase slightly over 400,000 victims. Another 200,000 victims died inside the camp or were selected as 'Muselmaenner' inside the camp, and were thus incapable of offering serious resistance.
Yet there are accounts and sources which indicate that for all four groups, i.e.
- victims selected on arrival at the old ramp and taken to the 'Bunkers'
- victims selected on arrival at the old ramp and taken to the crematoria
- victims selected on arrival at the new ramp and taken to the crematoria
- victims selected inside the camp, as Muselmaenner or in the Gypsy and family camp actions
there were occasions when the orderly procedures broke down. There is a documented breakout attempt in the Bunkers phase and other reports of unrest and resistance; the 1943-44 phase saw an attempt at a revolt/mutiny among the condemned ijn the undressing room which led to the shooting of SS NCO Schillinger; the 1944 phase saw more attempts to break out and flee as well as the refusal of Greek Jews to join the Sonderkommando; and there was resistance to the liquidation of the Gypsy camp.