Hello This old Harman does not have the removable panel to clean the chambers behind the fire brick like the newer models. Naturally, the dryer vent brush was used first to poke up in each accordion tube but to get all the ash out, I used 150 PSI of compressed air. See video http://www.youtube.com/watch?feature=player_detailpage&v=FCwc-L40ILQ Then, with the wire wheel, I cleaned and then coated the fire brick and panels underneath with the Dry Moly Spray. Now they look better and are really slick. Many people do not have the time to paint the fire brick so this seems like a good protective solution. Has anyone tried the Dry Moly on their panels and fire brick?