Colloidal silver is expensive to buy, but you can make it yourself quickly and easily. This is a step-by-step demonstration of how I make CS. When I make a batch, it lasts a long time, so it had been about a year since I last made some. I have used it for eye infections, sore throat, burns (with bandage), and toothache (it even helped ease the pain of my friend whose teeth were totally destroyed). Some people recommend regular use to strengthen the immune system and ward off flu, but I prefer to use it only when needed and only in small amounts. Using it this way, it's just about impossible to get argyria. Those whose skin discolored all used large amounts (2 cday to 1L, which is crazy) and mostly used silver protein or a silver compound such as silver nitrate. My family and I have been using it for medicinal purposes for years and, as you see, we are still not blue.
There is a lot of hype about argyria but I think you really have to use a lot of it for that to happen.