If it works only once it's hardly usefull. [Except Caro implements even more methods to reduce Corruption but that would totally defeat the point of corruption as game-mechanic.] HIGHLY Likly to happen: There will be more challgenes in the future game content the hero suffers corruption to get a rare item or beat a challenge or open a door or whatever-
It's better to restart now and beat the avaible cotent with a rather pure Hero than getting puniched a few update laters.
Murphy Hand was planned to be a last resort item against powerfull bosses. Now it has become a Newbie-Trap, giving experienced players a nice laugh: "Schadenfreude".