I suppose the heading could have been How Does It Work? But isn't Village technology wonderful. If there's something they haven't got, they'll make it out of something they have, even to the point of converting something like a simple hairdryer! Its use in ‘Once Upon A Time’ might be to revive Number 6 after the brawl with Number 2. Or more likely its use is to help keep Number 6's mind regressed to his childhood.
A hairdryer is also employed during ‘Fall Out’ in something more of a traditional way, in helping make the “late” Number 2 a new man. But in reality, it's simply the property department making good use of whatever they had to hand at the time!
I'll be seeing you - after I've been to the hairdressers!