bartleby claims the source to be alteration of dipsy-do, baseball term to describe motion of a screwball, from dip.

I doubt it. My SWAG (= Stupid Wild Ass Guess) is that the baseball term sounds exactly like the sort of thing that would have been coined by Jay Hanna "Dizzy" Dean, who pitched in the 1930's. Dizzy was one of the all time greats and was also sensational in his quotability (e.g., "It ain't braggin' if you go out and do it.")

Of course, the next question would be whether the pitch was named for the dance, or vice versa.