A couple of suggestions. First of all is using digestive bitters to aid with digestion and to cleanse the liver. Bitters work by contacting the bitter receptors on the tongue. This in turn stimulates the vagus nerve, which in turn increases digestive secretions and cleanses the liver. Drink plenty of water throughout the day when using bitters. Spring water is best.
Second would be to get some zinc tablets, roughly 20mg. Suck on one of these tablets three times a day until completely dissolved. They don't taste very good at first, but you get used to the taste. Zinc is a great breath freshener and helps with digestion and body odor as well.
Cut back on protein intake. People tend to eat way more protein than they need. Protein is harder for the body to digest and contributes to ammonia production in the body. The diet should be predominately vegetables, especially dark green, leafy vegetables. These are also great sources of chlorophyll, which can also help.
If this does not help then the next suggestion would be to work on the intestinal flora with prebiotics and probiotics.