Let me give you a real life example of how great "cooked" rock is.
I have been in the process of upgrading my 180 to a 300 gallon cube.
This process has been going on for about 400 years or so it seems to my wife.
I started "cooking" the rock in my tank and some really skanky rock I got in trade.
I "cooked" this rock for a few months, then took it out of the tubs, let it dry, so I could build the rock formations for my new setup.
This rock had been out of water for 4 weeks when I finally got around to setting up my new tank 3 Sunday's ago.
I put this rock in the new tank, filled it with water, brought it up to temp and dumped my fish and corals in with absolutely no fear of an ammonia spike killing anything.
To be safe, I checked the big 3 levels for a few days.
All at zero.
You see, if the rock has been cleaned of the majority of phosphates and crud then there is nothing to cause a spike.
The bacteria on the small pieces of rock that has corals attached on to them simply multiplied in a few hours and I was good to go.
My corals have never looked better by the way.