If it's not cracked, or even if it is cracked, but the shell is clean, I use them anyway. If cracked, and the shell is dirty, I thaw them and feed them to the critters.
If the spin test shows they're frozen, the yolk will show whether they froze all the way through. When the yolk freezes, it gels. When the yolk has gelled, it will remain completely round, instead of flattening out some. It's still edible, but you can't stir up the yolk or make runny-yolk fried, but they're fine hard fried, or hard boiled.
Any egg that may have frozen I keep for my own use, and make sure not to put them with the eggs I sell.