You really don't need to get carried away with a bunch of chemicals and abrasives. The glue is water soluble. Warm soapy water works without worrying about screwing something else up. Really! I too have had to play the CHP game with my side windows.
If you start at the top the water will kind of puddle at the point where the film meets the glass, this helps break down the glue. You just keep spraying and pulling. Use the blade for the tough spots.
