I use mineral oil to preserve eggs for long term storage, since having working electricity is not a guarantee and I prefer to have things which do not require a freezer for preservation. The eggs get a little runnier, but it still lets me be able to separate them into whites and yolk if I am making mayonnaise or boiling eggs - unlike freezer kept eggs that are supposed to be scrambled before freezing for best quality. I think my eggs would do better and not get a little runnier if they were kept colder instead of at room temperature, but am working on how we can get a "cellar" for colder storage of food items. Right now I just pack them into a carton and then stick the cartons inside of cheap foam ice chests that sit on the floor of my kitchen. We're eating eggs from April/May that are still good. Have been considering going to an oil/beeswax mixture for coating the eggs to see if that gives an even better impermeable shell coating.
I've heard of mineral oil as a preservative but didn't know of anyone who used it. I'll keep that in mind for the next overflow batch