I have been riding almost daily with the same helmet for 2 years now. I have just replaced it mainly because it has started to smell. Obviously sweat and bacteria. What tips are out there for keeping the helmet liner reasonably odor free. I am in AZ so you can imagine there is a lot of sweat inside in the summer. I do not want to pour bottled of cologne or perfume inside it that would be worse. So odor free is the goal.