One trope invariant in American cinema is that people go to New Orleans and weird stuff happens. (I can readily cite Tightrope from earlier in the same decade, and George W. Bush from this one.) This was a Mickey Rourke segue, one of his classic 80s efforts, guest-starring a Robert de Niro in full Robert de Niro mode. Even the devil could not do a better Robert de Niro than Robert de Niro.
So yeah, some voodoo, some weirdness... I don't know what to make of it. We're supposed to be concerned or interested about some kind of missing guy, but as the bodies pile up we wish there'd been a bit more characterisation of the bit parts.