I used dead rock in my return to the hobby. I wanted to get back in without the huge expenses so I recycled. It took about two months for the pods, worms etc. to populate the tank. It has been about 6 months and the coralline is finally growing well but my lighting was to blame for that I think.
I cleaned the rock, baked it (literally 450 deg for two hours) then baked it in buckets of salt water for a month. I baked it the first time to insure that the uncontrollable turf algae would never return. Most people get cute little hair algae, I had coarse Astroturf that drove me out of the hobby.
I set up the tank with the dead rock, new sand, and a couple pieces of rubble from the LFS and cycled it. I added blue leg hermits and fed them for another month. I added a couple of mushrooms on more rubble to test the waters. Then very slowly added more corals. I had a minor diatom issue but that is it. No hair algae at all. I have no fish but do feed my sun polyps heavily with no issues so the rock is again live.
I have to be honest, the tank looks like sh**. It gets better every day thou.