Your idea about using cayenne oil (powder is even better) was a great one. It does sting sometimes, but it is a phenomenal (sp?) healer for sterilizing and rapidly closing even large gaping wounds.
Still, if you are satisfied that your CS is working well on the hole itself, why not go the extra step & use your cayenne as an immune booster. Meanwhile, if you've had to start on anti-biotics - don't forget some probiotics to help offset their damage to your gut! I'm sure you don't want to trade in one problem for another!