I find it easier to use than other methods I've tried. The results also show less variation between trials, so I'd say yes it's effective. However, I have not tried to calibrate all of my lenses, nor do I plan to do so.
I gave up on trying to get the last quantum of sharpness out of my gear a long time ago. If that's your goal, I'm afraid I'm the wrong person to ask.
One of the biggest mistakes a photographer can make is to look at the real world and cling to the vain hope that next time his film will somehow bear a closer resemblance to it. - Galen Rowell