Peeking into the rock

There's this shanty I have heard a few times. It has Mexico in it, and it's not "Away Santa Anna," or "The Plains of Mexico," or "Round the Bay of Mexico." It's beautiful. It's slow, kind of like those, or "Bound for the Rio Grande." (which apparently refers to Rio Grande del Sur in Brazil, not Rio Grande del Norte in Mexico -- which I thought was actually called Rio Bravo in Mexico anyway)

I can't find it. It's so frustrating! I know I heard it on Youtube, but no combination of search terms brings it up there or on google.

What I remember of the chorus is:

"It's hard on the [something], she moves so slow
Hard on the something, down to [in?] Mexico"

Meanwhile, all this searching has turned up some impossibly macho shanty singing outfits, and also, apparently, Polish people love the Anglophone shanty musical tradition and sing lots of them in different contexts, sometimes translated into Polish and sometimes not.

edit: also there is a person who has uploaded every tiny little obscure clip from every movie they can find where someone sings a bit of shanty.