I guess that this method treatment would yield varying results, depending on the individual coin, and it's depth of 'patination'.
I have seen some late Roman bronzes where there is little of the original bronze left, to the point of none at all. All of the specimen was just 'patination' although it did look otherwise OK. In other instances, there would be a substantial amount of bronxe left.
I have heated a late Roman bronze in an oven (I can't remember the temperature), and the coin just broke into black particles when cooled. Total loss.
Fortunately, the coin was only a cheapie, but I am not inclined to repeat this method of treatment again.