I found a great site where someone used EZ Off Oven Cleaner, provided as a reference only. Make sure and wear eye protection when using caustic chemicals.
Otherwise, contact a local sandblasting company and find out if they can come in and bead blast it. It might be a little bit of money, but it sure would beat all that EZ Off, and working above your head for long periods is very tough. It might be too aggressive, though, too.