Unfortunately for bacteria, some bad breath treatments use alcohol or antimicrobial chemicals in an attempt to kill all the microorganisms in the mouth. Unfortunately for humans, such treatments rarely work as well as we'd like.
Alcohol may kill most oral microbes, but those that remain afterwards quickly repopulate the mouth and are that much hardier for having survived a bath of antibiotic solution. Also, alcohol dries out the palate, leaving the tongue and teeth ripe for bacterial growth, since saliva naturally keeps the little critters in check.
More effective treatments often target the odor compounds themselves while also addressing the moth's biofilm of smelly microbes. Research presented at the 89th conference of the International, American and Canadian Associations for Dental Research indicates that ethyl citrate, an esterase inhibitor, decreases the smell of halitosis 12 hours after use.
Esterases are enzymes that facilitate the creation of alcohols and acids. They are integral to the production of odor molecules. While this solution was found to work fairly well, it did not address the problem of the mouth's bacterial load.
Individuals who want to both neutralize their oral odor and push out detrimental microbes may consider using Aktiv K-12 Probiotics instead.