This is apparently widely known in various bawdy variations from college campuses to military bases. Three bawdy versions of "The Ring-Dang-Doo" are in Ed Cray's The Erotic Muse, 2nd ed. (University of Illinois Press, pp. 182-186). It is also in Guy Hogsdon, The Whorehouse Bells Were Ringing (University of Illinois Press, 1989, pp. 241-244). Like most of the other songs in this section, I learned it from Oscar Brand.