From my time in the northern climes, I reckon that the stable belt was a marvellous concept when modelled by a fit girly JO (fair enough they were in the minority compared to their larger sisters, but there were enough to keep morale high).
For foreign types such as myself, a tidy girly JO with stable belt, girly hat and lilting Pommie accent was one of the finest parts of RAF culture!
As for blokes wearing them I guess I'd concur with the earlier chiseller comments!