I do know that clipping nails, bathing and generally making presentable (!)a new corpse is usual. It's called 'laying out'. I suppose shaving a man post death would come under that heading too, although I've never 'done' a man.

The racial/racist aspect makes no sense to me- but then you've noticed the names of some fiddle tunes, haven't you? Tunes with names like 'Nail That Catfish to a Tree'; 'Moses, Hoe the Corn'; 'Give the Fiddler a Dram'; 'Dance All Night with a Bottle in Your Hand'; 'Sadie at the Back Door'; 'Waiting for Nancy' and tons more. Who knows what goes on in some benighted folks' heads!