You've written a very interesting post here. I like the remedies you recommend. Thanks.
Here's a little more information about one of the main chemical compound responsible for the smell of flatus and fecal breath, and that is methanethiol (also known as methyl mercaptan).
Methanethiol (also known as methyl mercaptan) is a colorless gas with a smell like rotten cabbage . It is a natural substance found in the blood , brain, and other animal as well as plant tissues... It is also one of the main chemicals responsible for bad breath and the smell of flatus. The chemical formula for methanethiol is CH3SH ; it is classified as a thiol. Wikipedia (click on Wikipedia to see their article on Methanethiol).
Here's an excerpt from an abstract of an article entitled, Biofilms and the tongue: Therapeutical approaches for the control of halitosis,
...although the dorsum of the tongue seems to harbour one of the most complex microbiological niches in human ecology, the knowledge of the role of tongue flora in health and disease is also very limited. Similarly, the nature of the tongue coating and the factors that influence its development and composition are almost unknown. The interest in the study of the tongue niche has increased in recent years due to its association with oral halitosis and to its role as a suitable reservoir for periodontal pathogens. The structure of the tongue favours a unique and complex bacterial biofilm, in which periodontal pathogens are frequently found. However, little is known about how to control this bacterial niche, and factors affecting tongue coating composition and aspect are not fully understood. Studies available on the influence of mechanical or antimicrobial approaches against tongue biofilm are very limited. Mechanical treatments showed a transient reduction in halitosis-related variables but were limited in time. Different antimicrobials agents have been evaluated: chlorhexidine, chlorine dioxide, metal ions, triclosan, formulations containing essential oils , and hydrogen peroxide... http://www.springerlink.com/content/kklgyab4e7t42m63/?p=71477f106169446f98310...