Hi Rhonda,
Doorway stretches and stretches in general don't help me either --- in fact they can cause flare-ups sometimes. I firmly press my finger in an area underneath my armpit (not in the armpit, but under it where the ribs and serratus anterior are). This may hurt pretty bad if the area is sore (it does for me when I'm flared up). While you are keeping pressure on the spot, begin to raise your arm up and bring it passed shoulder level -- and then stretch the arm with a doorway stretch or whatever. It only works for me if I pin that area and then do the stretch --- starting with the arm down and raising it up. That is the basics. I found a lot of different areas to pin and different ways to stretch/move the arm once pinned. The different combinations of pinning and stretching have released many muscles for me and greatly improved my function. It works very well on my surgery side. I am not sure it would relax the scalenes and drop the first rib for people who haven't had surgery.
I wish I had a video to show you --- I think it would be so much easier to explain and I could show you the spots that have worked for me. Be careful not to go directly in the armpit --- there are nerves in there and they can get irritated.