Homeowners can maintain their stucco interior or exterior siding themselves in a DIY progect. Indoor and outdoor stucco will collect dirt and stains needing care. In most cases for indoor stucco, a simple scrub with water is all that is needed to remove the dirt. For outdoor work, a garden hose or pressure washer needs to be used to remove the buildup of dirt. Then, a stiff-bristle brush can be used for remaining dirt and stains.