How many rocks are involved. In a small tank like that I would take out one rock a day and use a wire brush to clean it, rinse and use a soldering gun to destroy any residue.
if he cant fix it with the solutions everyone above said and he really wants to break it down i would just say get rid of the coral and inverts and just lower the salt level to 1.009 that way he can keep the fish and not have to go through a huge teardown process. the only thing with this is that the live rock will die also
