well my friend you suffer from the same exact problem i have my oral health is great but my breath is horrid i have tried all of the mouth washes like you said they work for about 10 min and then its back to hell i have had this problem for about 8 years i am 26 everyday i search these websites looking for clues on how to cure this problem i agree with your theory about whats causing the problem i have a post nasal drip problem that wont go away 1.i scrape my tongue.
2.brush and floss . 3use chlorine mouth wash 4.irrigate my sinuses. i do all of this and my breath is still horrid i live in northwest rainy moldy place
2 other things i am going to look into i took Antibiotic for Acne when i was a teenager i took it for a long time i wonder if this could have killed off the
good bacteria in my system also i lived in a house that had black mold in it this can be very dangerous i have heard well if anyone has any advise for me please tell me