Jon rightly calls this a “Surreal little number this one. We have a currently-dormant version of this with Bellowhead that may well make a comeback at some point. The melody here is a bit of a mash up of the Bellowhead tune and James & Nancy’s excellent version on Starry-Gazy-Pie.”
I’ll add a link to Mainly Norfolk that has versions from Linda Adams and a slightly longer one form John Kirkpatrick. It does seem most odd but then I believe that the simple explanation is that this is a conflation of two or three songs that all shared common elements. This Mudcat thread explains it quite well enough. The research looks to be better than I can muster, with the intrigue of the various feeds and the dual purpose religious and erotic imagery. I guess this is more a case of folk-confusion than the folk process as such and an example of how the oral tradition can carry something despite the meaning becoming obscured, or in this case seemingly lost completely. Still, nonsensical or not, Jon gives brings this to life and the line about “It is drinking of good liquor that made my heart to sing,” creates a kind of wayward logic to the whole thing.