Cleaning Large Advent speaker grill cloth

Having owned Advent's in the 70's with their off white grills, heres a great way to clean them without removing from the grill frames. The brown color in the grills is more than likely from cigarette smoke. Buy a can of Resolve high traffic carpet cleaning foam. Spray the grill until the foam settles than use a soft bristle brush and gently brush in a circular motion
than wipe away the dirt. Repeat if necessary. They will look like new. If you need new Advent badges for the grills you can buy them on eBay.