The origin of this is obscure, but 'scruff' can also be used for scurf, through a change called 'metathesis', which is simply a fancier way of saying 'transposition'. And since scurf can be a thin coating or layer on something, perhaps this is why we speak of the scruff of the neck.
|For formal occasions, Australians decorate their footwear with barnacles.|
About the only thing Australians don't use for distance throwing contests is the boomerang. They could do so if they wished, since there is a non-returning form of this device, but they don't, and neither does a well-aimed thong return, except when it is directed into a headwind.