That reminds me of the time I reduced silver nitrate with sodium borohydride. It went WHOOSH and a geyser full of silver and silver boride nanoparticles coated my hand and arm along with the bathroom sink and whatnot. Unlike if you take it internally, though, I was able to get it off me. Nothing a little nitric acid applied directly to the skin followed within a few seconds by water couldn't solve. Look, Ma, no silver, no burns!
I also blackened my hands several times with silver nitrate. Silver nitrate reacts with the salt on your skin to produce silver chloride, which is insoluble in water. The cure here is much less extreme: a thiosulfate solution is not toxic and not corrosive to skin, and complexes with the AgCl to render it soluble. Otherwise the skin will stay dark until a new layer of skin cells replaces it in a couple weeks.
The same quacks who sell colloidal silver also sell concentrated (35%) hydrogen peroxide as a cancer cure. Apparently you're supposed to put a few drops in water and drink it to oxidize away the cancer cells or something. But it has to be concentrated before you dilute it, because otherwise you could just buy 3% from Wal-Mart for $0.80 and deprive the snake oil people of money. Of course some people haven't gotten the "dilute it first" message and have severely, occasionally fatally, burned themselves by drinking straight 35% H2O2. A few have even gotten injections with entirely predictable results. Cure cancer with reactive oxygen species! It works for the ones who die, I guess.
But I've still bought it from them, because they're the only ones who sell concentrated H2O2 and ship it without paying the HAZMAT charges for shipping strong oxidizers, thereby making it cheaper in small quantities than responsible sellers. Then you can use it for things like dissolving thoriated tungsten electrodes to get the sweet, sweet thorium dioxide that I craved.
On topic: yes, obviously the technology the Chinese state is using to become a 21st century totalitarian cyberpunk dystopia are also applied against Americans by the private sector companies that are developing it, creating a dystopia only marginally different from the Chinese one. And, of course, it's still pretty buggy and basically every black guy is misidentified as a known criminal. This is what progress looks like!
