What would happen if I fed animatter into a black hole? Could this be a treatment to get rid of black holes?
No. Antimatter has positive mass just like ordinary matter, so the black hole would merely get larger and heavier.
Whatever fireworks happened inside the hole, if the anitmatter met up with ordinary matter there, would have no effect on the hole's total matter-and-energy content or, therefore, its mass.
— Alan MacRobert