A high-heat glass window or door is nice when new, but when it gets grungy, you lose your view. Today you'll learn how to clean a fireplace door, and windows in ovens, barbecues and more. Do you have a high-heat window or door with baked-on goo? From deep within the Carey Brothers' vault, we bring cleaning solutions out of the dust. For starters, to clean glass fireplace doors, spray them first with glass or window cleaner or your own mixture of vinegar and water. Then wet a spot on a soft clean cloth and dab some of the fine gray ash left in the fireplace. Then rub it on the dirty glass. The ash will permeate the microscopic pores of the glass, reducing surface tension and making cleaning a breeze. When done, buff the remaining haze. For more tips, visit our Web site at onthehouse.com. And that's the On The House tip for today.