Cleaning Baking Dishes Using Peroxide

Was it cream of tartar and white vinegar?

For an inexpensive cleaner (porcelain, glass, etc.) purchase Whiting in the paint dept. It's non-abrasive, super fine powder for polishing, cleaning glass. (It's primary use is for thickening paint, and is the 'white' powder that remains after polishing the car....it will not scratch glass; only your applicator does, so use a soft, cotton cloth).
1) Sprinkle Whiting on the baking dish.
2) Use a damp, soapy terry cloth to wipe away the burned, soiled dish.
Think your stove is clean?? Spritz the stove top and sprinkle Whiting and wipe away...you'll see the whiting find all those spots that still contain areas that aren't clean :))

I use barkeepers friend. Available at Walmart. It makes my white corningware look brand new again.