This is going nowhere fast. I'm not invested in this idea. It doesn't drive my thinking on the matter.
But, why not see who they are? Maybe they will face some real consequences for being bigots? Maybe they will gain an education.
I don’t think they are going to change their minds, especially when they are met with anger and hate... that will just fuel more anger and hate. The only way to change a hater in my opinion, is to have their “adversary” form a healthy bond and relationship with them. Holding torches and throwing rocks isn’t going to do that.
What kind of consequences do you want to impose on people who express hate towards others race/religion/gender/or sexual orientation?
I think you are somewhat right on how "to change a hater". Yet, since that "bond" has to be a two-way street, it's probably clear that the hater going into that bond is already somewhat willing to see the light. Most will not change, and many not even if someone of the hated group saves their life. That's just how it is.
So, if changing them is not an option (except for a few gifted individuals saving souls), the task is to contain the rot, no? For that, you have to have the haters out in the open - otherwise how do you even know there is something to contain, and where to find it? - but not in a way that would normalize hateful behavior, so that others would feel encouraged to adopt it. That, I believe, circumscribes the puzzle, and I have yet to see a good way to solve it.