D.B.
You can wash most backpacks on gentle cycle and then air dry. I'd use a fragrance-free detergent and then put white vinegar or baking soda in the rinse cycle to get rid of the odor. If you have to, put it through the pre-soak cycle first, with either vinegar or baking soda. They are great deodorizers. You aren't "deactivating" anything - you are washing it away.