> although the Spanish would have recognized it as a non-Christian practice to be stamped out, surely
As an occult practice, it may have been discouraged at least, but to say "non-Christian" makes it sound like one arbitrary practice extirpating another.
Rather, the Christian view (and certainly the Catholic view) is one opposed to superstition and the occult on the grounds that superstitions are irrational and immoral and thus opposed to the good of those who engage in them[0].
It is one thing for there to exist varying customs that are more-or-less arbitrary w.r.t. the signifier (greetings, for example), but the signified is no longer arbitrary.