i abandoned Italy as Epirus destroying everything i could and setting taxes on very high. in about 2 turns city turn rebel. same i've done with my most northern province as AS. they turned rebel too. and i've seen many of cities rebelling from a faction they once belonged. many times it happened with my help by destroying happiness buildings and having a spy inside. worked pretty well for me.
though it is a shame that one cannot simply erase city to the ground, some building are impossible to demolish