I have tried every brand of spray over the years and some gum up more than others. My personal favorite of the moment is the 505 temporary spray. But, as you have found out, a very light misting is all you ever should use and keep it away from the edges where your hands, scissors, etc. will be touching. I pin around those edges. My way is to spray lightly, let it dry a bit and then stick the layers together. After all is sandwiched, I still set it aside and wait a bit before sewing. Keep my needle clean with alcohol wipes. Clean the table or surrounding area if necessary with Goo Gone. And I spray it on the batting, not the fabric itself. A little goes a long way! I quilt nearly all day, every day and am still on a can I purchased about 5 years ago.
When washing, soak, do not agitate, in a large bin washer with some gentle soap (not detergent). Plain water does not remove the glue. Rinse well, dry flat or in gentle, cool dryer. You will be fine.