I read that article, seems a bit complicated for the home based gold leaching kit. I am aware of new nontoxic gold leach kits that use thiosulfate, bromine, chlorine, Iodine, and acids with catalysts. Ive heard that Iodine makes a stable compound with gold, albeit much more slowly than cyanide. I see these gold reclaiming kits on the web all the time, they're supposed to work, I also see nontoxic gold stripper for sale with plating chemicals in my jewelers catalogues. I would like to hear any feedback about what works and what doesnt. old 1970s circut boards have alot of gold on them, especially in the microchips, each little black plastic microchip has a tiny microprocessor inside soldered to a base with a droplet of gold, when you scan a large circut board there can be hundreds of these chips on them, not to mention the gold plated connector pins and "fingers" where it slides into the mother board. (or the motherboard for that matter), back in the early 90s I used to go dumpster diving and would find all kinds of electronic junk, I wasted most of it, sold the better stuff to some guys in california (like the ceramic chips). I salvaged some of the easier gold by electroplating the copper away from the pins and little copper foil fingers and boiling the remainder in (the works) toilet bowl cleaner (it has an oxide remover called EDHA in it that removes the nickel underplating), after removing the nickel all thats left was stuff resembling shredded gold leaf which I melted by mixing it with borax on a piece of wood with a plumbers torch. a propane torch will melt gold just fine on a piece of wood with a pinch of borax (wet it so that the torch doesnt blow it all over) -- all in alll it was a total pain and probably not worth the time, a stripper that would just dissolve the gold would have been about a hundred times faster and gotten a much higher yield.