Hot answers tagged equipment-care
It looks like the waterproof coating is flaking off. Try washing with a cloth and warm soap and water. I've had reasonable success with this method in the past.
Just a suggestion, you could try putting a small amount of something abrasive (such as rock salt or perhaps gravel) into the bag, closing the bag securely with a zip tie on the zipper pulls & placing it in a clothes drier on the Fluff setting (no heat) for some period of time. Or if putting it in the drier makes you nervous, you could try agitating it ...
Only top voted, non community-wiki answers of a minimum length are eligible