Something worked for me and I hope it will help those who suffer as well. All my life I looked into mouth thinking, it was teeth, I brushed till my teeth got erosions. I had no post nasal drip so I thought that is not the case for me. But when I swallowed, I always smelled that decay somewhere but still that no, I have dry nose and no I have no drip. But few days ago, I irrigated my nose using mix of water/h202 and brushed way back my tonsils! Keeping the electronic brush to the sides so I wont gag. BOY, MIRACLE. I DID THIS BEFORE BED AND NEXT MORNING. NOW FOUL TASTE OR BAD BREATH. NOT EVEN MORNING BREATH. SO IT WAS FROM NOSTRILS AND TONSILS. I HOPE YOU WILL GIVE IT A TRY!