I would only add that in one version Ronnie Drew stops the song to remark that they had to leave the most obscene part out, which is substituted by the two foot stomps, or hand clamps after langeroo before 'to you' . I always thought it must be a two-syllable profanity, but the authorized version above mentions the audience could supply 'Balls to you' which makes sense in that 'langer' is also slang for the male member, so "Langeroo. Balls to you" is good, unless one of yez can think of a suitable two-syllable profanity that would be appropriate.