Never has there been a ND/AD when the hammer was down on an empty chamber.
It is impossible.
Of course not, all the NDs happen when the hammer is dropped!
Which brings us to clearing barrels.
Dropping the hammer brings the potential for a loud noise and seems an unnecessary risk.
The only trust worthy safety is an open action. Control where the muzzle is pointed and double or triple all safety procedures and everything should be fine. I store with no ammunition in the firearm, the rest is academic.
Only step beyond that is a chamber flag with BCG resting against it.
ECIs are a good plan in may situations and the selector should be on safe when on is in the chamber.
