Chalice question

[Kheldron]

How do you use the Chalice?

I was pretty convinced that it would allow a "heal allies" or "cast item spell" on the equipped leader but...nothing.
I tried to equip an afflicted leader, hoping he would be healed next turn...nothing.
So?

That's kind of a noobish question but I never had before the opportunity to grab it in MP and would never inflict a tart factory on the poor AI in SP.