Anything you do takes knowledge and know how. There is no tool that replace this.
If you don't have it... Well, then you'll get it.
With piston stop weather it is rope, metal or plastic plug or something else, you can damage piston, cylinder, rod bearings, clutch itself even and more.
With wrench manual or impact you can damage just about anything.
With rod and hammer you can damage a lot to, but usually just fingers so saw is OK.
I think it is best to go with what works for you. I use impact sometimes, one some rare occasions I use piston stop, but don't like it. I mostly knock them of as the one I do mostly agree with it. Not much force, just one hit well placed is all it takes. Less risk to hurt something...