Quote Originally Posted by Lamprey
In other words, recruit 6-8 imams in other provinces and march them into the heresy region en masse. Don't send them in piecemeal or they'll go heretic.
Agreed. Best bet.

Or send in an Imam with 6 piety or better and crush them all with that one Imam.

I believe an Imam or priest above 5 piety cannot be turned to the dark side. They have "cardinal"-level immunity.