Please read my post in its entirety before making judgement.
I have had bad breaths for 3 bleeping decades due to excessive used of antibiotics when i was a kid. Over the years, I've tried pretty much everything under the sun includes Zinc supplement, hydrogen peroxide, chloryphyll, activated carbon, tonsilectomy, baking soda, Smarthmouth, Therabreath, candida meds, etc, and even paid $500 to have a dentist looked at the biofilm in my mouth under a microscope and implemented a special mouth rinse made by him. Nothing works!
Below is the routine I religiously follow and I can tell my malodor is 90% gone. It may not work for all of you but i can almost gurantee that it will for most. Various studies concluded most cases of halitosis originate fromt the mouth unless you have some other underlying causes like diabetese, Gerd, other med conditions, etc. So most likely your bad breath is coming from the mouth.
1. Scrape the living day light out of your tounge as far back as possible. The gagging reflex should subside with time. Just be patience.
2. Use oxygenating toothpaste on teeth and tounge. Anerobic bacteria in your mouth dislike oxygen.
3. Use " dental" probiotics, not the one for your gut. (What?? Probiotics didnt work for you? Please read on) The label should say dental/oral. Most of the probiotics for your stomach wont survive the acid in the gut thus rendering it less effective than the probiotics specifically designed for the mouth.
The bottle i purchased is one tablet dissolved in mouth in the morning and before bedtime. I went the aggressive route and took 2 in the morning and two at night. Within 2-3 days i noticed the coating on y toung turned white instead of the usual nasty yellow gunks. Sorry that was kinda graphic

I wont name the brand since i dont want anyone to think i have an ulterior motive. Just google dental probiotics and you'll get a list. If you really want to know just PM me because the one im using is quite effective, at least for me it is.
G'luck and thank me later ..smiley.