Basically, one can hardly trust any sea chantey lyrics, in English anyway, to be authentic. They got cleaned up at least twice, once so the old timers felt they could publish them and sing them around women, and once to make them politically correct. I don't really believe it was impossible to publish or at least write down the actual words to those chanteys - it was that Hugill and his colleagues were just too embarassed. The "dirty" lyrics you hear usually sound as if made up by Oscar Brand or the boys in the Beta House, not by 19th Century British sailors.
Some of the more authentic-sounding chanteys were actually mae up by A.L. Lloyd.