Or pull the ECU, but it seems like in the world we currently live in, removing an ECU from a car is too difficult for most aspiring tuners.
Plugging in a single socket is usually faster than removing the ECU... But yeah I agree on the "removing ECU" part.
IMO before you flash an ECU you need to have all the tools and knowledge to clean up your mess if something goes wrong at least on those ECU's where it is still possible to do that.