Senator Ron Johnson Now Peddles Mouthwash As A Covid-19 Treatment: His Advice Exemplifies The Rising Tide Of Anti-Science Ron Johnson promotes Covid-19 conspiracy theories and the use of drugs that have shown no evidence that they are effective. His latest foray into quackery - promotion of Listerine as a Covid-19 treatment - encapsulates the rising tide of anti-science that he and his fellow charlatans encourage.