I bake and decorate cakes, as a second income, and use washable bags for my frosting. Over time, the bags seem to develop an odor of stale shortening, which I can't seem to get rid of. The bags are not cheap, so I can't keep replacing them, and the odor doesn't seem to transfer over to the cake I am working on, but it just bothers me that I can't get rid of the odor. I don't like the disposable bags, because they are too stiff, and they're not cheap either. I don't have a dishwasher to wash them in, but I try to use really hot water, and even let them soak, but it doesn't matter. Any suggestions on what I should use?