I gleaned this article off the net, here is the text for storage with out refrigeration, this would be simular to coating with a petroleum jelly.

To use lard or shortening to coat the eggs, first melt the grease and cool it til it begins to solidify again. Dip each egg in the melted grease individually and set them on a paper towel to dry. When the shortening or lard is dry on the eggs, rub the eggs with a clean towel, removing excess solid grease. Rub gently and buff each egg. Now repeat the process, before the shortening solidifies. Work fast, allowing the shortening to get almost solid before re-heating it.

Line the bottom of a flat box with a clean soft towel. Place the eggs in the box in a single layer. Cover the box with either a lid or another towel. Place the box of eggs in a cool, dry environment. Eggs prepared this way will last up to 6 months, although I have heard people say that they have kept eggs this way for 1 year if they are kept very cool.

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