A cleaning apparatus for microsurgical instruments of the type having screw-type mechanisms used to advance or retract a plunger has a hollow sleeve into which the injector is liquid-tightly inserted, the sleeve being configured to hold the plunger in a fixed position when the plunger is disengaged from the injector body. A cap having an inlet port is liquid-tightly attached to the sleeve and cleaning liquid is forced from a syringe into and through the inlet port, flushing detritus from the injector. Various sizes and shapes of sleeves are used to accommodate different injectors.