Here is what you need. A cheap spray bottle (you probably have an empty one laying around). In this bottle mix a 50/50 mix of 100% acetone and dextron/mercron automatic transmission fluid. The two fluids will separate like oil and vinegar so you have to shake the bottle well before spraying.
I mixed up a batch and let it soak for 15 minutes on the rotor and with a few taps it came right off. Yesterday I spent 6 hours with 2 cans of the commercial brand with no success. My other rotor was equally rusted, and came off the same with this stuff only.
Hopefully this helps someone else out too.