Bad Breath

An article at kawanblog outlines 60 uses of vinegar including this one.

20. Apple cider vinegar and honey as a cure-all: use to prevent apathy, obesity,
hay fever, asthma, rashes, food poisoning, heartburn, sore throat, bad eyesight,
dandruff, brittle nails and bad breath.

So apparently apple cider vinegar and honey could be worth a try.