Just leave it outside the tent in bear country and the bears will lick the honey off -- do not be inside the bag , especially if you are ticklish. Just kidding.

Have you thought of asking a professional dry cleaner it there are options?

Do so at your own risk, but I had a bag that I washed many times on the whites/hot setting. It lasted for many, many years and if washing it in hot did anything, I did not notice. No matter what, it sounds like you are going to have to wash it or have it washed.