In the past couple of years, out of pure interest, I've tried actual silver nano particles (X-pensivo!), "pure" colloidal silver protein, "pure" colloidal silver "solution", reduced silver salts producing absolutely pure colloidal silver, electrolytically produced ionic silver with a 13% (max. byproduct) of colloidal silver and straight up STS method.
The only ones that worked were the (oft applied) electrolytic solution, and the "guaranteed" STS method. I briefly corresponded with some people in the ivory towers, who simply told me maybe I should have even tried to "rub a silver dollar on the plants while doing a rain dance" (a fancy cannabis PhD's exact words, not my own), to make sure I didn't know what I was doing...
The absolute plain truth is that only IONIC silver, the primary product of electrolysis, is responsible for sex reversal. Anyone who claims it's "colloidal" has never tried, or spent the money to use absolute colloidal silver, and is only worth what they used, which was a solution of IONIC silver with a minor species of colloidal.
As far as "toxic" goes, it's all silver IONS anyways... I'll pretend there's a difference. All I know is that thiosulfate is essentially nontoxic, and the amount of nitrate... well, we all know how plants hate nitrate...
It's all about TITRATION. How low can you go... funky chicken and all....