340 Not firing on all cylinders

I do it the easy way, by pulling all the plug wires from the distributor cap and just lightly set them back in.
Start the car and pull one at a time until the one I pull makes no difference.
That's the dead cylinder.
Then compression test that cylinder.
If the comp test looks ok, then I change the plug/wire.
If that does'nt do it then I look for a vacuum leak.

I know everyone says "Dont pull a plug wire without grounding it somehow"
but I have never had a problem or caused anything else to fail doing it this way.
EVER, and it makes it really easy to find the cylinder that's not firing.