"Conspire" is the wrong word to use in this case. The Sonderkommando, the ones who did the dirty work of facilitating mass murder such as body disposal, were not volunteers, but rather individuals the KZ guards chose because they were physically fit to work. Sonderkommando duty meant that the individual in question was not immediately murdered, but it was still a harsh life in which routine violence kept discipline. One incident at the Sobibor illustrates the depravity of this type of coercion. According to witness testimony at the Sobibor trial, one Sonderkommando begged a guard to kill him. The guard then instructed the camp cook to give the inmate a full ration of food and after two weeks, the guard asked the Sonderkommando if he still wanted to die. The inmate replied with thanks that he now wanted to live, after which the guard shot him dead saying "now you wish to live, but now you must die."
This incident at Sobibor illustrates how the camp system kept Sonderkommando in line. Minor concessions like access to food were important as many of the non-selected Jews were simply being worked to death. Arbitrary violence on the part of the guards was not the exception but the norm and Jews that selected for immediate murder were made keenly aware of their position at the very bottom of the camp's social hierarchy. Primo Levi's accounts of Auschwitz often spoke of desperate attempts to stave off the guards' violent inclinations by making themselves useful to daily operations. Such attempts could bear fruit, but the logic of camp administration meant that Sonderkommando would themselves be periodically murdered and replaced by a new set of arrivals selected for labor.
Levi would famously call the camps the "grey zone" in which conventional moral norms went out the window and there is much in the biographical details of the Sonderkommando that justify this assertion. Survival was predicated on making oneself a useful cog in the machinery of mass genocide. Non-participation was not really an option. Some Jews within the camp system abused their limited power, especially in a hybrid work-extermination center like Auschwitz where the guards delegated some control to certain inmates. Survivng Sonderkommando accounts also speak of the work parties having access to food and other perishables carried by those just exterminated. But it also needs to be stressed that many Sonderkommando used their survival to husband resources to resist and not just survive. The Sobibor and Treblinka uprisings were composed of Sonderkommando and other inmates. Five women involved in the Auschwitz Sonderkommando managed to smuggle in homemade explosives in 1944 to blow up one of the crematoria as part of a larger revolt. Such revolts were violently suppressed and speak to the difficulties of resistance inside an extermination camp. As terrible as the gas chambers were, the penalties for revolt and escape were even more sadistic and torturous. Being selected to live carried its own set of burdens for the Sonderkommando, but they were not responsible for the process of mass murder.