I've been using Ken's sinking catfish sticks, plus algae pellets, for what feels like years, but possibly only 1, and am looking to add some variety. Any suggestions?
Blackworms are the closest thing to an aphrodisiac for Corys, although bloodworms and mosquito larvae are about as good. Frozen are nearly as good as live. IME triggering spawning usually has more to do with changes in water quality, flow and temperature than diet, but good food can be/is a great help.
I agree with all the other advice, and specifically with Sam's advice that spawning is more related to things other than food.
I feed my corydoras Repashy (meat pie and community), sinking pellets (lately using small sinking cichlid pellets), and a variety of flakes (lately have been using Cobalt and also flakes from www.almostnaturaltropicalfishfood.com). I also supplement with microworms and white worms.
I don't advise when it comes to fish except to say, "don't". Merely relating my experience/prejudices/marginally qualified opinions, never advice. Those what listen do so at their peril.
Let me restate: my personal experience, while limited and not capable of generalization, is quite similar to the anecdotal evidence adduced by others in this thread.