Give them the reports of the free blacks in America that also owned slaves and watch their heads spin. Not super common but it definitely happened. Really erodes the narrative.

Course slavery was horrid regardless of who is doing it but you can't really go off so hard on the racial equity and reparations shtick when you have documented evidence of black people enslaving other black people and white abolitionists trying to put a stop to it.

Granted that whole era anyone you pick would be considered a racist by modern sensibilities anyway. Loads of abolitionists still thought that black people should be kept separate or they were inferior or whatever even if they recognized the evils of slavery and the rights of the slaves to be free. How shit like Liberia happened.

Got all the neo-segregationalists back now trying to fan the flames of racial strife again. Same old tune different verse, you may not get along with your neighbor but don't fucking let that prejudice pass on to your kids generation. Let them come up with their own reasons to hate each other.