It is some powerful stuff. I swear by it. I'm a fan of MMS for attacking a sickness already in the system, but nothing can compare to oregano oil for a preemptive attack when symptoms first present themselves. I get a pot just steaming, not boiling. Put a couple of drops of oregano oil in it and slooowwwly breathe it in. You WILL cough when you first try it because it is very harsh. But if you get it thoroughly into your sinuses and upper bronchial area it will destroy any critters.
You can also make pills with a couple/few drops in a gelatin capsule. This will help more internally as more of a preventative measure. Wear gloves when handling the oil.
My favorite preventative measure is liposomal Vit C. I'm getting about 4-6 grams of C into me every day with this method with no digestive issues. FReepmail me if you want to know how to make it because it is pricey to buy.