You can tell things are going well when your students start teaching you. One of my students recently introduced me to this essay on 'Othello as Protestant Propaganda'.
If Iago is a reminder of Sant Iago, a duplicitous, Jesuitical character who also just happens to be a "Moor-slayer", then we have a rather different view of the play from the one we may be used to. Othello's "sword of Spain" from Act 5, Scene 2 gains a wider signification for a start.
If nothing else, such a reading provides a useful counterbalance to the glut of "Catholic" readings of Shakespeare that we have seen in recent years. Clearly Shakespeare was emerging from a Catholic world (and a Catholic family) but he emerged into one that was strongly Protestant.