TS Server Guru
No it does not work like that.That doesn't work. Where does the electricity go if it's not connected to a ground? It stays inside the power supply.
Pressing the power button after it's turned off would only drain any electricity in the motherboard or peripherals back into the PSU. Which is good, unless you plan on opening it...
When you press the power button on a PSU not connected with a power cord the power stored in the capacitors is discharged and put to use, for example spinning the fans which you can see if you discharge a PSU this way.
However I must stress that this is not a safe way to discharge a PSU, because it assumes the PSU is working properly, which as I said before it most likely is not if you feel the need to open it up and fix it!