While this is a good idea, I think it may actually CAUSE a Negligent Discharge. The only way to check to see if there has been an accidental discharge (on a firearm without an external hammer) is to pull the trigger and see if it goes CLICK. Remember, the two loudest sounds in the world is a CLICK when you were expecting a BOOM and a BOOM when you were expecting a CLICK.
I don't know about others but I will NEVER dry fire a weapon unless I KNOW it is unloaded for certain. I don't mean it wasn't loaded at 8am when I put it on I mean I JUST removed the magazine and physically and visually inspected the chamber.
Not to say this idea is bad, just saying if you are going to do this maybe take a round of spent brass, put a little bit of masking tape over the primer, and at the end of the day eject the brass look at the primer (which is covered in tape) and see if the tape is dimpled....you can place the empty brass in the chamber with tape over it and pull the trigger the night before so you know what it'll look like if the firing pin did infact come in contact with the taped primer.