Hi Julian,
We are always changing toothpastes (do other people do this? I have noticed this to be something of a macro phenomon) Right now we have about 6 different tooth pastes in the cabinet- everything from dentie to something called Kingfisher, which tasts like anise. In any case, I have noticed from experience, if bad breath arises
it is either from too yin or too yang.... try umeboshi. If that dosen't work, drink some beer. Beer usually does the trick for us, though. Victory Ale, Hop Devil or Lager is very good quality, traditionally brewed beer. Serria Nevada and Red Hook are also very high quality, too. Good luck!
Elizabeth