People don't like to hear this, but the majority of self-described "fascists" I've met in my life grew up. Their stupid worldview stemmed from a place of dissatisfaction, delusion, or a desire to get a reaction out of people. When you attack them outright, you feed into their fantasy that they're persecuted instead of just mentally ill.
Plus, you're still not looking at the shoe on the other foot. What happens to your witch-hunt when people justify annexing Crimea or Ukraine "because Nazism" and ridicule you for demanding patience? Do you honestly think the popular movement can tell the difference between right and wrong when propaganda is afoot?
Are you worried that lies will be too effective? Right now we live in an information ecosystem where lies outnumber truth, and additional lies are quite effective by building on that base of existing lies. If truth were to vastly outnumber lies, I think it'd work as inoculation.