I come from a long line of disgraceful people on my mom's side (some... lovely... people) and have just decided to leave it be. We cut off relatives who still believed in the practices mentioned, moved and are happy out. The thing is, these people are just common blood. They are just relatives. They haven't got your brain, your thoughts, your beliefs... Don't let it bother you. End the stream of bad people, just acknowledge it happened and leave it be other than that. Look into activism for the parties involved who are still struggling - as someone mentioned about WWII for example, donate to foundations for Jewish people, Roma, LGBT etc. Even in your own community, it's still a change. Good luck.