I'm pretty sure that Kant would say that, if everyone were to feed sailors to werewolves, there would no longer be sailors, and our shipping routes would cease to function and society would crumble, and thus we would be violating the categorical imperitive. Thus, feeding sailors to werewolves is probably not a moral thing to do. However, if you decided that not killing someone was probably the right thing to do (as murder volates the categorical imperitive) and then the person you didn't kill goes off and feeds a bunch of orphans to voracious ninja dolphins, you still did the right thing. This is in conflict with the view of utilitarianism and J.S. Mill, which states that the intent does not determine morality, only the sum total good that the action brings. Thus, if you follow utilitarianism, Vanilla Ice did great things for music, because the entire alt-rock and indie rock movements were both at least in part a response to shitty 80s rock.
However, Nietzsche would be all for you feeling sailors to werewolves, so long as A) it doesn't violate your virtue, B) it increases your personal power, and C) brings you closer to becoming an ubermensch.