I'm a Ziploc bag-washer. I just can't bear to throw out those freezer-weight bags when they've only been used once. Problem is, some bags rinse more cleanly than others. For those bags that really shouldn't do double-duty with food, I store them in the car to act as self-sealing trash bags. That way, when my kid eats a banana and is left with the (rather fragrant) peel, she can seal it up in the bag and throw the whole thing away when we get home.