I use an older (read not-for-good-dishes) green scrubby with Dawn and baking soda for stuff like that. Takes a bit of elbow grease and patience, but it works.
I dampen the scrubby, put a bit of Dawn Ultra or Platinum on the scrubby, dump a little baking soda (1/8 - 1/4 c, depending on the job) in a small dish, dip the scrubby in the dish, and then start scrubbing on the polymerized grease. I do this with cooked-on grease on the cooktop, too. Works rather well.