Vinegar works. I wouldn't worry about residue. There wouldn't be enough of it to do anything.
When I take out a piece of fabric to see if I want to use it or if it enough or for whatever reason, I always fold it a different way when I put it back. Try to get the folds in a different place.
I use Sta-Flo. I dilute it with water: 4 oz. Stay-Flo to 12 oz. water. I use the bottle (from the expensive spray starch) that I've used for at least 5 years, and mark the oz. with marker so it is easy to see. That is a very good sprayer. Diluted that way it costs me .04 cents an ounce.