Art Blaster and Graffiti Blaster from J&J Chemical can be used in combination for the removal of graffiti on portable restrooms in the field and yard. Art Blaster is a powerful liquid graffiti remover, cleaner, and protector designed to quickly and easily remove graffiti such as paint, marker, and even pencil from portable restrooms. It leaves a protective sheen with a green-apple scent and is designed for use servicing units in the field. Graffiti Blaster is a gel-like liquid that clings to the sidewalls of portable restrooms while cutting through the most difficult, baked-in graffiti. It is designed for use when cleaning units in the yard. 800-345-3303; www.jjchem.com.