Canning Butter and Waterglassing Eggs

Butter is is quite simple to can, but it is a bit time consuming so when I do it I do a lot. Waterglassing eggs is a simple process, but you can't use the eggs you buy in the store. In order to be sold in the US you have to wash your eggs first. Washed eggs are on their way out the moment you wash them in tap water or abrade their surface. There is a protective membrane that you do not want to damage. So eggs you're going to do this with must be easily brushed off and little more. Generally speaking this rules out duck eggs. I wonder sometimes if they're aware they're laying eggs or if they just fall out. I can see it now.
Mertice: "Lucy! Something just fell out of your butt and into the mud."
Lucy: "What?"