I've used a similar process, but without the nastyness of having to shellac/oil the egg shell. Clean egg with a sanitising agent, dry, and seal using a vacuum sealer (like that used for meat), making sure that each egg is in its own "compartment" (otherwise, once opened, you must use all the eggs in the bag). I've not tried it for longer than a week, but even in hot temps it seems to work. I like the idea of cracking each egg into a cup beforehand, in case one has gone off. I've never had that problem, but it seems worth it, considering near-zero effort could literally save the bacon...
Bryan