so... if you have 10 of them that's still only 9 scales every 3 hours.
which would take you... 100 hours.
I have 24 so that's 24 scales for about 15 minutes of work. I get there is a cool down but i wont sit at my computer waiting for it to come up.
with perfect drops thats 3.125 hours of playtime 37.5 hours of real life time of sitting at my computer watching my cool down expire.
I think it is fair to say a lot of people who have been through the Halloween event where they were able to mass clear it have suited their entire crew (average size of 12) with DT clickies. So double the numbers above and you are still looking at about 6 hours of play time without really having to have a tank that can pull the entire zone.