An aqueous poultice composed primarily of methyl cellulose was formulated for use in the removal of imbedded grime from a monumental weathered Carrara marble sculpture of <i>George Washington<i/> at the National Museum of American History. The poultice was applied, allowed to dry, and removed as a film. To evaluate the treatment, films were analyzed using atomic absorption spectrophotometry and scanning electron (SEM) microscopy in conjunction with energy-dispersive x-ray analysis.