Dissolving Egg Shell I know that an egg shell is made up of approximately 92% Calcium Carbonate.  The remaining percentage of the mass is a protein matrix.  I know that vinegar (5% acetic acid) dissolves the Calcium Carbonate.  Does any other food (such as lemon juice or some other acid) dissolve the shell of an egg.  If so, how long does the process take?

I want to dissolve the shell of the egg before I soft-cook it.
Someone once had me on in a pub that you could pickle eggs by simply placing a raw egg in a jar of vinegar and the energy released by the shell dissolving would hard boil the egg.

When I got back home I put a raw egg in a vinegar filled jar. Immediately air bubbles appeared around the shell as some chemical reaction kicked off.

The shell was completely dissolved in about 3 days. The egg was raw and no doubt gone off since it had been denyed its naturally given vacuum pack, i.e. the shell.