Is there a way to actually use Plenary Indulgence?

[LathusWHM]

First things first: The tooltip lies. You always get a confession.

Second things second: It seems like it's only really good in savage raids, where you are casting multiple aoe healing spells in succession. If the confessions lasted longer it'd be very interesting heal in almost any content. I hope that's what happens.

You only get a confession if it does healing. If they aren't missing health and its 100% overheal then they do NOT get a stack.