Shook swarm seems to be the answer for everything with the NBU at the moment, unfortunately the BBKA ethos has got right into the soul of the organisation the last few years.
There is a leaning away from S/S (for foulbrood) with the inspectorate and a feeling that a straight destruction is much more effective.
The trouble with shook swarming an EFB colony is that, it's pointless doing it in isolation at an apiary.
What you get when you S/S a hive is a cloud of totally confused and distressed bees milling around, their fresh 'home' is at first lacking the scent and pheromones to attract stray bees back so you have beees trying to beg their way in to whatever colony they come across - EFB usually flares up in stressed busy colonies at the height of season, so no colony is going to turn away a young, fit nurse bee which would take the stgrain off an overworked nursery, so next thing, they have just taken in a 'Typhoid Mary' into their midst.
I think for shook swarming to have any effect, it has to be done to every hive in the apiary.
So.......... that's my only justification for conducting a shook swarm chucked out the window - happy days