This is how I tried to eliminate odor from my Synapse. It went through the rain in Berkeley for about 30 minutes and I can't seem to get rid of the funky odor since.
Last January, I was in Thailand and I figured sunlight might help. It actually helped, there's still a hint of odor left. I'm ordering MiraZyme and see if it can completely kill the odor.
P.S. My mother borrowed the bag for her 2-week trip, and she loved the bag! Looks like I have to buy another Synapse. :)