How could you ever clean it? It's more like "Assume every gun is loaded till you check it and then check it again".
Muzzle in a safe direction, and no fingers anywhere near the trigger (unless, as happens with one I had, cleaning involves removing the trigger group from the receiver. But by gum I treated that receiver/barrel group like a loaded gun even when the trigger group was in the dunk tank on the other side of the room...)