So I am a bit confused on how to use this thing. I know you can either ground by connecting it to the plugged in but turned off PSU or bond by connecting the strap to the case. Which one is better? Also, I heard that the PSU or Case can't be painted for the strap to work. Is that true? My case is a Fractal Define R5 and my PSU is an EVGA 750W G2 80+ Gold.