Douglas Harper's Etymology Dictionary
1847, "false cheap material," perhaps an alteration of hocus-pocus, or from the nonsense chorus and title of a comic song (Hokey Pokey Whankey Fong) that was popular c.1830. Applied especially to cheap ice cream sold by street vendors (1884), in Philadelphia, and perhaps other places, it meant shaved ice with artificial flavoring. The words also were the title of a Weber-Fields musical revue from 1912. The modern dance song of that name hit the U.S. in 1950 ("Life" described it Nov. 27, 1950, as "a tuneless stomp that is now sweeping the U.C.L.A. campus"), but it is said to have originated in Britain in World War II, perhaps from a Canadian source.
Wiktionary
alt. A group dance performed in a circle, in which people move various of their body parts in and out of the middle, and shake them all about. n. A group dance performed in a circle, in which people move various of their body parts in and out of the middle, and shake them all about.
Usage examples of "hokey-pokey".
But she'd seen shagging before—sometimes with three or four or even more doing it all at the same time (sometimes with partners who were not precisely alive)—and the hokey-pokey wasn't very interesting to her at her advanced age.
Maxine finished dancing the hokey-pokey, saw Keith at the door, tossed her shocking pink plastic whistle to Dionne Huffman, and said, "take it from here.
Probably because she danced the hokey-pokey with German housewives for three hours after school every day.