Stank Helmet

[songofsixxpence]

Alright so I have a pretty much new helmet, I've been riding in it for maybe 2 months. and oh my god, it smells sooooooooo bad. really bad. like a thousand sweaty bodies died in it and then a thousand sweaty horses rolled on the sweaty bodies. How can I make the terrible smell go away? My hair is usually pretty clean (as clean as it could stay at the barn) and i cannot wear anything underneath except a hairnet.

Short of stabbing it and creating vents or botoxing my head what are your creative ways to keep your helmet (and mine!) smelling like mountain spring air?