I have had the same general experience as 4seventy, so I generally avoid lowering the tumblers on an ejector DR by pulling the triggers while closing the action.

I use a de-cocking bar of my own making. It works just fine, and there is no problem re-assembling the rifle after the tumblers have been discharged on the de-cocking bar.

My de-cocking bar is a piece of 1/2" diameter brass bar set in the base of a shed deer antler. Here are a couple of photos:

You hold the end of the brass rod firmly against the standing breech, over the firing pin hole, then pull the trigger. The brass absourbs all the shock of the falling tumbler, preventing any damage to the firing pin. You can see some marks on the end of the brass where it has been dented by firing pin blows.

Curl