Doesn't work for me, and I have not completed Nightfall. Tried using it four times. None of those times my helmet changed, nor did I hear the sounds. Drops out of Hive Majors or Ultras pretty good. Just like Black Wax or Silken Codex, but much less likely. I could farm the Cosmodrome room for thirty minutes and received a total of three Jacolytes. Does not matter if the Hive are on Earth, the Moon, etc.