The invention features in-situ cleaning process for an ion source and associated extraction electrodes and similar components of the ion-beam producing system, which chemically removes carbon deposits, increasing service lifetime and performance, without the need to disassemble the system. In particular, an aspect of the invention is directed to an activating, catalytic, or reaction promoting species added to the reactive species to effectively convert the non-volatile molecular residue into a volatile species which can be removed by conventional means.