I have pulled a couple cartridges with a tap and a cleaning rod.
You sacrifice a couple cartridges to use to find the tap that will 'just' bite into the case neck, and then tap it loose with a rod.
Use a little common sense (which pretty much means that Sunray's "advice" is pretty much useless) and you will cause no harm. Get heavy handed, and like as not, the potential is there.
Cheers
Trev