Terry was explicit about saying that some of the dirt lay in the word "hogeye" itself, but he declined to be explicit about what it meant.

...Singers could imagine whatever they chose.

True, that's what I was vaguely alluding to by saying that people may have "later" imagined a dirty meaning (which becomes just as valid as earlier meaning) and/or that discourse about it (e.g. Terry's) may have oriented shanty-types towards expecting something dirty.

My current opinion is that the "original" meaning was clean, but, something like "Hilo," now "lost" to us. Not necessarily a mondegreen, not necessarily vocables, but then gain not necessarily something with a whachamacallit (declarative?) meaning. In other words, it was not necessarily meant to make any direct sense. Course that's just my opinion.

My opinion BTW is quite influenced by the evidence of the plantation or minstrel songs. I think it most likely was a word that was passed on from the plantation song, without thinking/caring about the meaning. Then later on it may have been ascribed a meaning when borrowed by a different cultural group.

This is a very broad statement, and highly contestable, but my sense is that the Black culture (or Southern U.S. culture?) that may (!) have produced this song originally is one that treated the "meaning" of words in songs in a different way than, say, RR Terry's culture-- which sought a rather more direct, rational meaning for all words in a song. Terry (hypothetically) would *have* to find some explainable meaning for "hogeye" and just as many of us have (including me at first), he suspected veiled sexuality.