A front-loader washing machine with vinegar & baking soda in the "pre-soak" slot and vinegar & baking soda combined with a "gentle" clothing detergent like phosphate free, fragrant free stuff already mentioned (arm & hammer, ivory snow) in the "main cycle" slot should take care of anything in even the most wretched bag. Warm/Warm. Drip dry, hang it upside down and open or with the back of a chair inside the bag keeping it open & upside down, front flap on the backside of chair.

This will do the trick on any bag made primarily of nylon. If your bag has an outer of polyester or a blend....I have no idea, maybe lighter fluid...and a match.