I am in the same process as you.
I picked up 170 lbs of previously live now dry rock, it was left dry for about 7 months. I brought it home and blasted most of the debris off with a pressure washer and let it dry out again for a couple weeks. I then placed it in two tubs with; RODI saltwater, a power head and heater. When I first put it in it smelled a bit fishy. I let them sit for 3 weeks and did a water change this week. They no longer smelled at all but the water was a bit yellow. One strange thing is that any dead HA that was on the rock pretty much broke down but there was a rock that had a couple dead zoas on it and they didn't break down at all. I manually removed any remnants and so far the water is crystal clear and smells great. I am using the Jungle AIO dip sticks and everything looks good on those too.
One thing I am going to do is grab a Phosphate test kit and see if the rocks are leaching Phosphates and if so I am going to try the LC trick to remove the Phosphates long before I set the tank up.