I like your attitude. But I don't quite have your patience, because I believe the pay-off drops sharply at Step 2. I generally respond to the first angry, self-righteous, snarky bit of drivel by completely ignoring the invective. If there is a discernible pony amid the horseshit, I simply reply to the point being made as if it were offered respectfully. That allows the hothead to cool down and reassess.
But if the reply to my Mr. Nice Guy post is venomous, I conclude that the person in question, whether or not they could be tamed, is not worth my trouble. I don't OWE it to someone to help them become nicer, and I don't need to foster conversation with people who PROBABLY can't be fixed and PROBABLY aren't worth fixing. Life's too short for rescuing trolls from themselves. But I don't block. I ignore. Blocking deprives me of information about an enemy. Why would I do that?
(I'm not sure we're using "troll" alike. Some people are just smug scolds. They might better be called "bullies" than "trolls." Bullies are merely insecure; trolls are mischievous. But I may be wrong, as I have never understood why anyone would want to be a troll as I understand the word.)