sir:
My CZ 75 came with a plastic "snap cap". Insert this in the chamber, hold gun downward, jiggle it into the barrel, release slide, and you're good to dry fire.
If your CZ didn't have one, I would suggest getting one from CZ-usa.
I also believe that because it is only plastic, when it is removed by racking the slide, it can't damage the ejector etc. or any of the stuff inside the gun.
I want to buy a pcr so I am lurking here.
regards.