Rinse your mouth with Peroxyl from Walgreens or 50/ 50 solution of water and peroxide and good bye bad breath. It will kill all the old bacteria accumulated in your throat and mouth through the years and you will have fresh breath forever. Just do it once a week or month.
This will work, however if there are cavities or cavities hidden under any crowns you may have., the bad breath caused by the old bacteria will go. The cavites have to be taken care of to eliminate the total bad breath.