Afraid not, no chewing gum, mints etc..
But I have read that you can use a certain make of breath freshener strips....can't remember the name at the moment. I'm sure someone will come back with the answer.
Im aware of not being aloud to, but still do. Its never affected me, I cant deal with that taste.. but then i also drink diet coke on it, Still loose as much as people that dont.. maybe thats just me though x