I put mine on a gentle cold cycle. There are some enzymatic cleaners like Nature's Miracle that you can dump in the wash to get rid of any lingering smell. White vinegar and baking soda would probably work just as well. I pour both of those into my load to get rid of mildew and odors. Then I just let my backpack hang-dry overnight to avoid fraying or melting in the dryer. If it's synthetic material it will dry in a few hours. Good luck!
Yes, you can. Just be sure to clean out all of the wrappers, etc., that might be in it, and zip all the zippers shut before putting it in the washer. Put the laundry detergent (the kind with NO bleach) right on the spot, and use warm water to wash it.