That float test tells you nothing about whether the eggs are safe to eat or not. The older the egg the more moisture it loses. That moisture is replaced by air. At some point it loses enough moisture that it stands on the bottom of the pan of water. A little more loss and it floats. The float test tells you how old it is, not whether there is something wrong with it.
You can sniff them. If they smell like rotten eggs get rid of them. If they don't smell like rotten eggs you can cook them for your chickens or dogs. You can compost them. You can cook them for your family. In any case crack them into a separate bowl before you use them to get a better sniff and see what they look like. Odds are they are perfectly good to use.