So in my current game both the Ottomans and myself founded religions and went Fealty. The problem is that due to the pressure policy, both of use get more pressure from the other person's religion than our own in each of our cities. This creates a very awkward situation where tons of our faith needs to be used on clearing our own cities of foreign faith non-stop. I'm starting to think fealty should always apply double pressure from your founded religion to your own cities. It's bad enough that genocide seems like the only solution.