Colloidal Silver vs Oregano Oil?

Which is better for flue/cold/allergy/mold/infection ??? And what is up with 10 ppm to 500 ppm om Colloidal silver based on the brand name? How do I know which I need ??? I think I like both Colloidal Silver and Oregano Oil, but I also read somewhere that Colloidal Silver is a big scam....?? Any one knows about anything??