When I last used my BGE I cooked 2 boston butts for 17 hours. I placed a drip pan under the grill and the butts right on the grill. Yesterday when I went to use my BGE the grill, the ceramic ring, the dome and some of the left over lump was covered with mold(it looked like an old loaf of bread). Has anyone seen this before? It probably was 3 weeks between usage. I scrubed the grill got the temp to 400 and let it stabilize for 10 -15 min. before using. Would anybody do anything differently?