The guy is using collodial silver, not collodion. Collodion is gun cotton dissolved in ether and alcohol. A colloid is a suspension of one substance in another, like milkfat in water, aka milk. This is in contrast to something that is dissolved by a solvent like table salt in water.
Silver is an antibacterial agent and a lot of folks believe drinking collodial silver has health benefits. That practice leads to argyria and the symptomatic blue skin.