If you haven't already, give a listen to the "music performance" video from the cannibal club website.

The act of eating human meat is different from participating in the torture and killing ritual. One can eat the meat without being the killer. Logically, eating the meat is a step to being invited to a ritual kill. Witnessing a kill is a step to participating in a kill.

This "performance" is done in the presence of people eating human flesh. It is a re-enactment of the sounds of the killing ritual for those that have already participated in it. It's a desensitizing preparation for those that intend on participating.