Re-potting from lava rock

[elibrown81]

I am planning on re-potting an Alcra. into s/h. It is very root bound and currently potted in lava rock. (not my choice, it just came that way) I have re-potted other Onc. types from lava into s/h, and often the roots have really taken hold of the rock making it very difficult to remove all of the old media. Since the old media is in-organic, is it as important to remove ALL of it before the move to s/h? In my past experience I have been very aggressive in removing all of the rock, sometimes resulting in quite a bit of root damage. Should I just leave the rocks that the plant doesn't want to easily give up, and in doing so, spare it unnecessary root trauma?