Hard-boiled the egg how you wish. Now, the next step is key. Cool the egg down slower than the heat rate used to cook the egg.
So this method is rooted in 2 basic principles of science; heating & cooling. The basis is a gradual cooling period will allow the heat to escape the center of the egg in a more continuous fashion. A quite large temp shock will cause the outermost layer to endure more stress as it transfers heat too quickly to the ambient coolant. Over time, that membrane will soften up.
I've read other hints and tricks from other websites and to me, it all seemed a bit excessive. The only thing I haven't experimented yet is the age of the egg. But since the age is subjective depending on factors like how long was the carton sitting at the store shelves, I would use the expiration date as a demarcator. Please let me know how this goes. Comments?