It sucks to find out too much about people sometimes. I got friended on FB by a guy I did some volunteering with this summer (and will do so again next summer)

It sucks to find out too much about people sometimes. I got friended on FB by a guy I did some volunteering with this summer (and will do so again next summer). Turns out he's a racist, transphobic bigot. So my question is, do I just start laying into him until he learns something (and damage relationship with someone I have to work with), or do I just unfollow and hold my nose later on?