Apart from the stagnation of the saliva for a longer time, people who are accustomed to mouth breathing during sleep are more likely to have fouler morning breath as they would encourage the production of bacteria. Note that anaerobic implies that these bacteria only live in non-oxygenated environments. You must be aware that alcohol dries the mouth. What's the big deal about it? Bacteria that cause bad breath breed on dry mouth. This is the reason why it is advisable to people with bad breath to drink plenty of water to moisten the mouth. Mouthwash is effective if used correctly and if the alcohol content does not dry your mouth. Because practically, most people with halitosis have their rooted problems on the over production of volatile sulfur compounds in the mouth. If left uncontrolled, these compounds would cause the foul odor to emanate. Volatile sulfur compounds are the by product of the workings done by the anaerobic bacteria which are helpful in the disintegration process occurring in the food and the decomposition of dead tissues in the mouth. Tooth brushing may still leave food particles in our mouth especially in between our teeth since toothbrush cannot clean the entire surface area of the teeth especially the cavities. These food particles will decompose. And like other decomposing matter on earth, food particles inside our mouth emit unpleasant odor. Aside from brushing your teeth and using homemade toothpaste, use dental floss at least once a day. This ensures that the food particles hidden in between your teeth are removed. Food particles when left out inside your mouth can breed bacteria that breakdown sugar and protein and produces volatile sulphur compounds (VSCs) which cause bad breath. Some of these food work by leaving trace odors inside the mouth while others would promote higher acidity level. Smoking also contributes to the development of unpleasant smell. Aside from the smoker's breath, substances such as nicotine, tar and odor-producing compounds could accumulate in the soft tissues of the mouth and the area surrounding the teeth.