Just an update for you all that posted tips.

Last night I went out in the backyard with my dirty dish, a can of
Easy-Off Oven Cleaner, garbage bag, rubber gloves and mask. Sprayed the
dish and left it overnight.

The results were amazing. My deeply crudded, scrub-proof, stained, 8x8
Pyrex Baking dish is as good as new. And with NO SCRUBBING! I can't
believe it. All I had to do was rinse and wipe down. I'm running it
through the dishwasher just to be safe.

Thanks for all who provided the tips. I love the Internet.