I've heard that but pretty much ignored it since it's an endgame reward. I generally don't play after the ending. I'll start a new game.
I think it's the stun/stagger that has that effect. Early game, a good baseball bat or tire iron works very well for that if you open with a strong attack from stealth. Gag Order is more reliable and works with any weapon, even ranged attacks. If you have a Cyberdeck, Sonic Shock also has the same effect if you follow it up with weapon attacks. No trace and no alert if you are using silent weapons... or if you're far enough away. I've blasted enemies with a shotgun and gotten no trace with either Gag Order or Sonic Shock first. As long as they can't hear the shot or see you, they won't know where you are.
