When David Whitlock was asked, "Why does a horse roll in its own filth all day?" his life was changed. Driven to answer this question, he decided to quit bathing and hasn't in fifteen years.
Whitlock found that the reason horses roll around in their filth is to rub living bacteria into their skin. This living bacteria protects the flora there. He has since made a spray that harnesses good bacteria that neutralizes hazardous substances and organisms on the skin. It also breaks down the compound that makes stink sweat in the first place, ammonia.
Check out this video where the guys from Buzzfeed try out Whitlock's spray product Mother Dirt.
Full article and interview available