Westinghouse had an interesting self cleaning system. Only the broiler element came on full blast to clean the oven. Above it was a sort of reflector that was a thin chamber of the smoke eliminator with little holes above the loops of the broiler element. You could clean the porcelain reflector pans by placing them on the sides of the lower rack and leaning them back against the walls of the oven. It worked well and seemed easy on the porcelain.