Doesn't work. That was actually a libertarian talking point at one time. But don't work. And the reason is that there's no such thing as an absolute dictator. Every dictator is dependent for his rule on his supporters. And the supporters choose to support the dictator for what they get out of it. So the dictator allows his supporters to be ruthless so that he can stay in power. You aren't trying change the mind of one dictator. You are undermining the support structure which the dictator is dependent on for his survival.