Abstract: An aerosol dispenser and applicator assembly for cleaning and lubricating the sprocket chain of a chain drive. The dispenser comprises a sealed can filed with a liquid lubricant and a gas propellant. Projecting above the upper end of the can is the hollow stem of a spring-biased valve, such that when the stem is depressed, emitted therefrom is a lubricant mist. The applicator is formed by a headpiece having a pair of parallel jaws cantilevered therefrom and supporting respective brushes in opposed relation to define a twin brush whose bristles are flexible. Formed in the twin brush is an internal channel which snugly accommodates the sprocket chain to be treated when the twin brush is pushed against the chain to cause the opposing bristles to yield and admit the chain into the channel. The headpiece includes a depressible actuator key on whose underside is a hollow socket which receives the stem when the headpiece is seated on the upper end of the can.