Sonderkommando. A useful idiot, who, in the death camps were put to use for a period of time... and then killed off to bring in new “workers”. Communists use people in the same way. For example... in the Ukraine prior to Holodomor Lenin and Stalin valued the “organizational”capacity of the muslim populations— their imams— to motivate farm collectivization. Robert Conquest wrote about this, i believe. They got them to move onto the huge collectives, then killed the imams, and the starvation of the Holodomor took the rest. Population solutions of the Lenin-Stalin era.