Thanks for links.
Recognising "virtue signalling" as a way of getting a front seat in the secular afterlife - only if the separation method gives more return for effort will the "alternative" method get used - displacing the mercury method used for centuries in South America. I must finish watching about "The Monado Method". It was found that gold miners in that village used the fronds of a particular tree as the means to catch gold in a sluice - rather like a "highbanker" used in North America by prospectors if I understand right.
----------------------------------------
There is a theory that the "Golden Fleece" of legend was based on using the natural grease in sheep wool to trap fine gold particles. The grease, Lanolin (cholesterol etc), is still valued for clinging to and protecting metal surfaces.