A method for forming and imploding cavities within a cavitation chamber is provided. A hydraulically actuated piston is withdrawn to form the desired cavities and then extended to implode the cavities. The cavitation fluid is degassed prior to hydraulically driving cavitation within the chamber. Degassing can be performed within the cavitation chamber or within a separate degassing chamber. In one aspect, a coupling sleeve is interposed between the hydraulic driver and the cavitation chamber. Preferably the coupling sleeve is evacuated.