Abstract: A method and apparatus for on-site removal, efficient cleaning, and expeditious restoration to service of the diffuser lenses, i.e. diffusers, lenses, and reflectors, used in fluorescent lighting fixtures. The apparatus employs dual immersion chambers, deep troughs, filled with a liquid medium suited to ultrasonic transducer agitation. It comprises a rectangular cabinet, having longitudinal slots in the top that provide external access to the troughs. The narrower trough, with appropriate liquid contents, serves as the initial scrubbing or washing chamber, while the wider trough, with differing liquid contents, serves as a rinsing and article-recoating trough. An ultrasonic transducer is horizontally disposed within a niche in one of the walls of the wash trough. Diffuser lenses are cleaned by detaching them from their fixtures, placing them one at a time into the washing trough, where they are cleaned by ultrasonic liquid agitation, and then into the rinsing trough.