Gummy cruddy pan. Ammonia. Plastic bag. Fresh air.
Bagged up pan with a slosh of ammonia. (Overnight)
Pretty clean pan (except where I got tired of scrubbing the corners).
I plan to repeat this method with my bigger, nicer baking pans. I did think the overnight ammonia soak would remove the dirt like magic, but I still scrubbed at the gunk with Barkeeper's Friend and a scratchy pad. Still and all, the results are fine.