Halitosis can come from the nose, the throat and the chest, as well as the gums. You need to check out the various areas.
The nose. Postnasal drip, yellow discharge, nasal congestion- these may be the halitosis origin.
The throat. Thick mucus from the nose the sticks to the back of the throat is an ideal breeding ground for odor causing bacteria. Fix the cause from the nose. Usually the problem is that the nasal cilia are not moving the bacteria out of the nose rapidly enough. The Hydro Pulse Nasal/Sinus irrigator uses a pulsatile stream for this.
Tonsils: . Here bacteria are in the deep crypts or holes in the tonsils. Pulsatile irrigation via the specially designed throat attachment will crowbar these bacteria out.
Gums: Good oral hygiene is best. If you have severe gum disease, a periodontist is a MUST. Gum disease can cause SEVERE health problems plus loss of the teeth.
Tongue: A tongue scrapper is useful to remove food stuck in the crevices of the tongue.
Lungs: A lung abscess may be a cause.
Generally drinking lots of fluids prevents halitosis. Add lemon or lime to your water plus honey. This thins mucus and makes it easier to remove stale mucus.
To repeat, if you suspect gum disease, it is ESSENTIAL to get that taken care of FIRST. If you have serious gum disease, a mouth wash is NOT the answer nor is a toothpaste. Best is your dentist or a specialized dentist.