If my back of the envelope math is on point, STS recipes have ~30ppm of silver; I cut my solution ten times, so theoretically it has ~12ppm silver. Sprayed the female that failed to turn thru the old crusty sts. Not necessarily looking for a methodology, yet, just a proof of concept. The next attempt will use clones of an individual to test different concentrations
Found one for cannabis, that uses an 8 minute boil to reduce the silver.
Extract of 10g cannabis (leaf?) in 100ml water
1:1 v/v with
5milliMole AgNO3(aq)