Those preoccupied by their guilt are much like the religious people whipping their back rather than going out and doing actual good deeds.
White-guilt is rather self centered. How about empathy for those who need it instead? You can help another person out of love, compassion and empathy. It doesn't need to be because you feel you owe them or because you feel guilt.
Too many are preoccupied with perfecting themselves. Erasing every tiny sliver or prejudice and racism they may have. That is easily a fools erand. It may be more effective use of ones energy to fight against deep racist convinctions and beliefs because there are still plenty of those.
There are still plenty of people who even reject racism as an actual problem.
There is a propaganda war being waged. The alt-right is flooding social media with half truths promoting racism. Everyone could put in at least some small measure of effort against the falsehoods, by educating themselves on the issues and push back.