That might work, but it would take a long time. Maybe there's some way to convince them that their 12th. Imam is here and wants them to make peace with their neighbors.Most jihadis are brainwashed into believing lies.
One solution to this would be by using the same tactics. Pay some "lukewarm" religious leaders or even charlatans who aren't even Muslims to dilute the jihadist propaganda. It's something that will take a long time but there's much this sort of thing could achieve.
Holographic projection in the sky?