When I got into this hobby somewhere around 96. One of my lfs i frequented literally took his live ocean rock outside and power blasted/cleaned his ocean rock with his power sprayer. He did this on several occasions throughout his cycle and cure process before he sold his really good rock. He would sell it straight out of the box with dead and dying stuff on it for much cheaper.
What he accomplished by curing this way is fast removal of unwanted algae, dead corals etc. Im finding out now that also means super fast reduction of Nitrates and Phosphates along with all the other benefits of removing undesirable algae and critters.
You could did this in separate container really easily in pretty record time depending how diligent you are with cycle and curing the rock. Would be a great way to seed your "dead" rock.
I had my fiji rock sitting in sump with gulf rock and by 6-12 months together. My fiji rock was pretty well seeded with all the fan worms, bivalves and sponges that came on my gulf rock.