Interesting! Thanks.. I have had great success using 100% Simple Green..Spray on, wipe off. However I don't wait for the gooey mess to bake on.
For my Memphis Pro, I made a deflector 1" x 27 3/4" angled @ 45º that sits at the front of the hopper lid to guide the grease laden smoke up and away. Really helps w/ keeping the hopper lid clean...