Here's another one of the pieces of evidence for my argument about the cotton screwing work.

This recording of a song sung by stevedores in Tampa (on the Gulf of Mexico) is not described as a cotton screwing song (that labor had ended by the time of this recording in the 1940s). However, it is a song about Mobile Bay. We might suspect that the stevedores of the Gulf ports, of which cotton screwers were earlier representatives, kept this song and/or the work method alive.

They stop/extend time after each chorus to "grunt," indicating the place of exertion.

"Mobile Bay" (1943)