I pose the same question. I had some stubborn ghost devices which clicking refresh and/or remove over and over again again from the hub did nothing. As soon as I got the stick and hooked it up, two clicks and the ghosts were gone. You can do lots of other cool poking of the devices with the SiLabs software as well so its handy to have.
I also have had the same issue with some switches, they get stuck during the pairing and create ghosts. Not sure if it was the hub or the switch. Once I got everything paired and ghosts removed its been pretty solid now, even with pairing new devices now.
I roughly followed this guide to get the stick up and running:
