Hi guys at minute 1:50 Beorn says that pressing the "O" Key I can clean a little bit the keys that are not been used, but ...

Hi guys at minute 1:50 Beorn says that pressing the "O" Key I can clean a little bit the keys that are not been used, but I think that in blender 1.78 that shortcut changed, What is the shortcut in the new blender? or the concept at least?