Not a blasted thing!
The "dokie" part is just a rhyme to make the saying sound cuter - it really does not mean anything at all except OK, which means "everything is fine."
To 'go south', as to "vanish, abscond," 1920s, Amer.Eng., probably from mid-19c. notion of disappearing south to Mexico or Texas to escape pursuit or responsibility, reinforced by Native American...