I've tried to find a queen in there to no avail. Will try again. There are still plenty of bees and they're agressive. If I shake them out is it to shut down the hive and make them beg into other colonies, and leave any queen behind?
Hmmm
In my experience (less than others here, certainly), if there is a queen, they won't beg their way into other colonies, they will just cluster around the queen (perhaps on the old stand, or on the floor, or wherever she goes) and then swarm off to find a new home, which is somewhat inconvenient for the recipient.
So personally, if they have not responded to a test frame (indicating that they think they have a queen), and definitely don't have laying workers (which would be indicated by lots of eggs splattered into cells, and drone brood), then I wouldn't shake out at present. I would continue to search for that queen
Waiting another week is a good option.
Another option, to help find the queen, would be to move the hive to a new stand (3m or more from the old one, facing another direction perhaps), which will shed all the flying bees (which will indeed beg their way into other colonies, as the queen won't be present for them to cluster on). That will leave just the nurse bees and make the queen easier to see. Or you could use a queen excluder to filter them somehow.