Aharon Varady, on the Facebook group, pointed out that "Anokhi" means "I" in Biblical Hebrew. Here's the bit in Transmigration of Timothy Archer
"Apparently the anokhi mushroom was toxic but the Zadokites found a way to detoxify it, at least somewhat, enough so it didn't kill them. It made them hallucinate."
I don't know if Dick was aware that Anokhi means "I" in Hebrew. He got deep into the Bible in English, but I haven't seen much to indicate that he was much interested in learning biblical languages. "Anokhi" seems to have become one of the many special jargon terms PKD adopted based on a superficial acquaintance with the (already kinda weird) research. I haven't looked closely enough at Dick's sources like the Allegro book, or the evidence about James Pike's beliefs. But those would be good places to look to understand this problem better.