According to the manufacturer, the smoke saturates your clothing and other gear with phenol, a naturally occurring antibacterial and antimicrobial. It also deposits lignin (the sticky substance found in woodsmoke), which keeps odor-causing bacteria from growing. (Phenol and lignin are also what prevents smoked meat from going bad.) Activated carbon is released in the smoke as well. Since the smell of smoke is common, goes the argument, it doesn't spook deer.