How do I Clean Stainless Steel Grill Grates With Steam? Whether your stainless steel grates are in a charcoal or gas grill, the grates accumulate ash, grease, and charred food and sauces with use. Removing this greasy, hardened debris from your grates after grilling is important, as the debris causes uneven cooking. This debris also burns and smokes, resulting in odors that affect the taste of your food and flake off the grates onto your fresh food. One way to soften and loosen this debris from non-clad stainless steel grates for quick cleaning is with steam. 1 Fill a bucket with cool water. 2 Pour some of the water over hot stainless steel grates after grilling to create steam. Wait 30 to 60 seconds. 3 Dip a steel grill brush into your bucket of water and scrub the debris from the grates until the bulk of the debris is gone. switch to a softer, brass brush or non-abrasive scrubbing pad. Dip the brush or pad in the water and continue scrubbing the grates until you've removed all of the debris. 4 Dip a softer, brass brush or non-abrasive scrubbing pad into the water and continue scrubbing the grates until you've removed all of the debris.