The mucous membrane does a great job at protecting the egg, and the mineral oil is a good (but lesser) substitute. Eggs can stay good for a long time if properly stored. Be a little careful of the test by floating, it's pretty accurate, but there can be some exceptions.
As for Europe, v.s. the US, please give it a rest. I spent a few years of my youth in Europe, and also on farms here in the US. We do just as good a job as anyone else in providing healthy quality food.