Well even if you cannot maintain the unrest over 100, you still force them to nerf their income and/or reduce their population by patrolling (also ties down the patroling units, and exposes them to attack).
You really should just test this stuff yourself. Get a copy of the debug mod from the mod forms and fire it up. Start a two player hotseat game with both as humans so you know where the other person is. You could test this in under 3 minutes once the mod is installed. Heck, you can probably cast the spells on your own provinces to test.