When I packed up the materials for the Tunze display at IMAC I bagged the corals and just kept the rock moist. It was out of the tank about 8 hours. A few of the rocks had zoanthids and
star polyps on them and they were fine. I repacked them three days later and brought it back to the shop with another 8 hours out of the water. Everything survived just fine.
Heck once I moved a tank across town and a firefish goby was hiding in the rockwork. It was -14 degrees that day and the rock was out of water for about six hours. The next day the firefish was swimming around like nothing happened.