Mouse Milk

Mouse Milk is the trade name for the penetrating oil sold by Worldwide Filter, Inc. of San Leandro, California. It has a long-running reputation in general-aviation maintenance circles for freeing rusted and seized aircraft fasteners — exhaust studs, control-cable terminals, and stuck rocker-arm hardware — where the consequences of broken bolts are higher than in a typical garage application.

The product is a non-aerosol drip-bottle formula. Worldwide Filter sells it as a single-purpose penetrating oil; the company does not maintain a broad catalog of detailing or maintenance products. SDS and technical data are published at mousemilk.com under the WWF-001 product code.