Chlorine dioxide is very effective. I've been making it myself for years. Effective in preventing influenza and other infections. Very effective when applied in the initial stages of the disease. You don't even have to drink. I spray it because chlorine dioxide is a gas and it passes through the skin. Mix 28% sodium hypochlorite solution and about 4% acid (can be vinegar or lactic acid) in a ratio of 1: 5. After 10 to 15 minutes, the liquid becomes yellowish or orange and should be diluted 3 to 5 times with water (preferably by smell, it should not be an irritating smell of chlorine). It can be stored in a plastic bottle with a sprayer for 2 weeks (in a cool place). It is ineffective when discolored and this happens quickly if the ambient temperature is high.