It’s very simple never machine wash any bag, backpack or pouch. Machine spins and it damages the fibers of materials used inside laptop bags or daily use bags. Best way is always fill a wash tub with normal tap water then add only 1 tea spoon of detergent not more than that, and simply spin the bag with your hand. Try rubbing with soft teeth brush to clear any deep integrated dust, but make sure do not rub any label, printing or embroider part because after contacting water they get weak until unless they again get dry. Never dry bag with spinner or any hair dryer as it can damage padding inside. Dry in open sunlight with all zips open and hanging upside down, if possible then even turn inside out too.