One other method I've heard of for preserving eggs is to dunk them in boiling water for about 5-10 seconds. This will cook the membrane on the inside of the shell and make it much less permeable, making the eggs last longer. It also sterilizes the exterior of the egg as a side benefit, reducing your chances of getting salmonella from them.
I'd also avoid coating the cans in anything that isn't safe to eat. Coating them in wax is probably safer than coating them in paint. Generally, when you open a can, there will be little particles of whatever the can is coated with getting into the food... Personally, I'm not too fond of eating paint.
Last edited by sailingdog; 03-28-2006 at 06:26 PM.