I'm not surprised that Westerners fail to perceive the essence of the it — this is an act of collective humiliation of junior employees who are made passive spectators of those disgusting orgies. It is a sublime message to his underlings — be my loyal shoeshiner, and maybe one day I will elevate you to a position where you can do this too.
Those middle age nobodies rarely if ever attend brothels just by themselves, the whole point for them doing so is to drag their subordinates into it, making them a part of the "humiliation pyramid." There is no "oiling of the deal" element here.