Many years ago I already had this topic in a similar form. At the time, I asked whether it would be possible to make powdered salt as well as powdered sugar. If you make your own popcorn with the standard hot-air popcorn machines, the salt sticks poorly. You can pour liquid butter over it, but the popcorn often becomes soggy and greasy. Now I have the solution. Simply spray baking release spray over it and add salt. It works wonderfully.