Care, (leaning & Repainting Cast Iron If your grille is courted in the floor, remove the grille when using household dealers and liquids near the grille If cleaners or liquids get on the grille it may start to rust. To dean your grille, use a dry death to wipe away any dirt and dust. If the paint on your grille becomes worm or the grille ls rusting you ray wish to repaint it. If there are any rust spots use a steel brush to remove the rust and thoroughly clean the grille.