Yeah don't do that anymore. Don't start the engine at all unless you're going to drive it long enough to get it up to operating temp and then some. If the car has to sit a month or 2, so be it. Worst case your gas starts to get a little stale and the solution for that is adding some fuel stabilizer, I like Lucas Ethanol Treatment (green liquid). I add that at every fillup on my old Mopars even though they get driven at least once every week or 2.
I have a neighbor down the street with a 3rd-gen Camaro drag car, he'll periodically start it up and let it idle with an occasional rev for a few minutes then shut it down. I mentioned to him once that's not a good idea and is doing more harm than good but I still hear it starting up and revving in his driveway every now and then, nice guy but he's a Chevy guy go figure.