Occasionally members have asked for advice on hulusis. Since after all this time I still haven't figured out how to upload photos, this type of hulusi is what I would choose:
Notice the drone pipes are the same length; the drone switch consists of just a hole. To make it work the drones have to be switched over so the hole is at the bottom. The hole is then covered by the right thumb; this make turning on and off the drone very quick.