I am a dental hygienist, and it sounds like he has a pretty good case of periodontitis. When plaque and dental calculus accumulate below the gumline, it can create pus and infection that create a foul odor. He needs to see a dentist.
A lot of plaque hides in the taste buds of the tongue and creates halitosis… brushing your tongue daily with a toothbrush or tongue scraper will help also. Alcohol mouthwashes are contraindicated with people who have dry mouth, smoke a lot, or drink a lot of alcohol… other than that, alcohol mouthwashes like Listerine are very effective when used as recommended. I really liked SmartMouth mouth wash –it does not burn and works well after you eat onions –from my own experience.
Perio/Gum disease can lead to abcesses. He could have an abcess in his mouth that smells bad also. Once the hard tartar/dental calculus deposits are present (tartar can form 3 days after not brushing or flossing), it needs to be professionally removed and no amount of flossing at home can remove it.
To treat periodontal disease, typically his mouth will be numbed with a local anesthetic and cleaned in quadrants; referred to as Scaling & Root Planning. We numb patients because gums can be very tender and sore with severe gingivitis and periodontitis, and hand scalers and an ultrasonic cleaner is used. His mouth would be cleaned in sections so we can spend an adequate amount of time to remove the bacteria and debris below the gumline. After, gums can be tender for a day or so –but most of the time the patients are very thankful and can feel that their mouths feel healthier. Warm salt water rinses, a prescription mouthwash, and Ibuprofen are usually recommended afterwards. If he is very nervous, they can prescribe a valium type of premedication for him. Some offices do sedation dentistry also if his anxiety is severe.
Most of the time it’s the wives and girlfriends that set-up the appts for their guys anyway. He can always set-up an initial evaluation or comprehensive exam; more of an exam, x-rays, and consultation –without any treatment the first day –this way he won’t have too much anxiety about having treatment the first day, and he can establish a relationship with the dentist.
Infected gums and teeth are linked to heart disease, stroke, low birth weight babies in women, and can infected gums be exacerbated in patients with diabetes, compromised immune systems, pregnancy, and birth control pills.
Emergency rooms are frequented by severe dental infections. Don’t wait until it hurts. Bleeding, bulbous and reddened gums, gums separating from the teeth, tooth mobility, and halitosis are symptoms of an unhealthy mouth.
Alternatively, it could be a stomach or gastro-intestinal issue, xerostomia, or post-nasal drip –but it really sounds like a dental issue.
Hope this helps.