I wash and reuse freezer bags, except the ones that had chicken in them. I know some people turn the bags inside out to dry. I don't do this because I always seem to tear the ends of the "zippers". What I do is take a section of a "select-a-size" paper towel, fold it in half and put it in the bag, then press the bag flat. You can zip the bag shut if you want to, but this is not necessary.
Check out these photos.
Washing those snack, sandwich, quart, and gallon plastic zippy freezer bags in the sink can make you wonder if the effort is really worth saving that money, but I have stumbled upon an easy way to continue being economical and "Green!"