I've had excellent luck with a schmear of neosporin covered for a day or two with a waterproof bandage that seals it in on all sides. The round 'spot' style bandaids are my goto. Clean the surrounding area really well with rubbing alcohol first so the bandaid sticks well, don't let the ointment come into contact with the sticky part of the bandage or else it ruins the stickiness, and reapply right away if it starts to come off. I always try popping it first right after a shower which works about half the time but either way it almost always clears up within 48 hours when it's completely sealed off with a bit of ointment. I think the mechanism at play is similar to the one that clears up warts by keeping them covered with duct tape. Getting the aim right can be tough so it helps to have a sympathetic ass-istant (har har).

*edit*
Looks like there is a handy all-in-one version but it may not completely starve the spot of air which I always guessed was a part of how this treatment works, that is a totally nonscientific guess on my part though.