This seems like a weird question. Utility depends on your goals. When I call somebody a racist it's generally not to change their mind. I am unconvinced that there was ever a way to do that. As we've discussed before, it's to create social pressure.
Good post. I use this phrase a lot (and perhaps it's too flippant), but you aren't going to be hugging any racists and turning them into reformed liberals. It just doesn't really happen; that is, it does occur occasionally (Byrd, famously) but that's like saying it's a good investment of your resources to buy lottery tickets because winning occurs occasionally.
It's better that we get to a point where racists live and die with their beliefs held secretly, and over time, with their ability to easily pass on such beliefs, you phase it out to lower levels. Converting racists is claptrap that people from Portland think is possible because they hold the belief that racists are just ignorant. Definitely not true; plenty of racists have met decent minorities that they would even call friends. They still believe those people to be subhuman, and their pleasantries are as heartwarming as a person petting a dog. They don't get points for being nice to your face if they still don't view you as equal.