From hootch (alcohol) and cooter (vagina). People who visited speakeasies were considered to be of low class and even lower morals, and prostitutes were often seen in and around speakeasies, particularly in large cities.
Made popular in America by Cab Calloway's song "Minnie the Moocher", in which Minnie is a compassionate prostitute who becomes very rich, and revived in Britain through its appearance on an episode of "Jeeves & Wooster" featuring Stephen Fry and Hugh Laurie respectively.
b) Wooster: I mean, all this ho de ho de ho stuff is pretty clear, but what do you suppose a hootchie cootchie is exactly?
Jeeves: It's hard to say, sir, unless it's in connection with one of the demotic American words for ardent spirits. I'm thinking of hootch, a word of Eskimo origin , I'm informed.
Wooster (amazed): You bloody well are informed, Jeeves. Do you know everything?
Jeeves (dryly): I really don't know, sir.
Its meaning is derived from the French "couche," past part of "coucher" which means "to lay down." The Hootchy-Kootchy (Hoochi-Coochi) or Cooch dance is a pseudo-Turkish, sensual dance executed only by women in short skirts, bare midriffs and tight breastbands, which is said to have originated at the Philadelphia Centennial Fair (May-Nov-1876.)
The term has been carried over to mean any so-called partnerless female "Sexy or Risqué" dance performed at fairs, Carnivals, Saloons and Burlesques clubs etcetera where women would be encouraged (or exploited) to perform such dances in a more provocative manner originally used to help gain attendance to sell alcohol to the patrons of a saloon etc.