I’ve been trying to find accounts of historical use of sinicuichi, but it seems very little information was recorded and the traditions have died out.

Sinicuichi is an interesting hallucinogen, causing yellowed vision and audio distortion. Unfortunately, its use is likely to result in terrible, painful, full body cramping the next day. Erowid has some accounts of contemporary usage: https://erowid.org/plants/sinicuichi/sinicuichi.shtml

There seems to be a theory that fermentation of the plant (leaving a paste of the leaves in a container in the sun for a day, like people do for Kanna) is necessary to remove whatever the toxic component is, but some of the erowid accounts report cramping after fermentation anyway.

I would love to know how this plant was used ritually - did they just accept the cramping? Is there a consistent way to prepare the plant? Are there different strains? Too bad we genocided everybody that could tell us.