OWT (Old Wives Tale) dead follicles cannot grow hair, only we the living can grow hair, so I say get out there and GROW SOME HAIR! When cadavers were disinterred it appeared to some observers that hair had grown, or nails had grown, but in fact, it is just the dessication of the tissue, shrinkage, in fact that makes it appear so, it does not happen.

The dead are shaved in cultures where there is a viewing of the corpse and the dead person had been a shaver, they didn't shave bearded men, or women who didn't need a shave!

Perhaps the tune is rather difficult to play, something one wouldn't care to do, like shaving a dead (n...) man? OR perhaps it is slang for some other occupation or practice?