You cannot do this with a rebellious city because when it revolts you get a rebel army turn up.

I did it once in carthage and a new Carthaginian army appeared in the city complete with War Elephants (and walls cannot be removed from a city to make it easier to take)... It was a nightmare retaking the place in order to exterminate again and reduce squalor and unrest.

Also often such an army cannot be bribed.