The best guess I have seen though is someone saying it is placentas from sex slaves. Because the spoilage timelines match up, and the scarcity seems about right. I even found a rabbi arguing that human placenta isn't unclean for Jews (using the argument that eating human shit isn't unclean for Jews according to some earlier ruling, no joke that was the argument.)
Most people think baby meat.
The best guess I have seen though is someone saying it is placentas from sex slaves. Because the spoilage timelines match up, and the scarcity seems about right. I even found a rabbi arguing that human placenta isn't unclean for Jews (using the argument that eating human shit isn't unclean for Jews according to some earlier ruling, no joke that was the argument.)