In just a few years, oral rehydration therapy (ORT) has become the standard treatment to reduce infant diarrhoeal disease mortality in the developing world. The paper describes an ORT intervention campaign in a rural area in Western Kenya (Kakamega District). After about a year of careful preparation, the campaign was launched in January 1986 and compared the use of a value-added product (flavoured sachets) sold through private outlets in addition to primary care distribution of an unflavoured sachet in an experimental cell (Bukura Division). In a control cell (Novakholo Division), only unflavoured sachets were distributed free of charge through primary health care facilities. Using local perceptions of diarrhoeal disease management, the campaign in the experimental cell was carefully designed and mass communication techniques employed and adapted accordingly. Outcome assessments of the campaign, which lasted until March 1987, included the overall ORT utilisation over time. Changes in perceptions towards diarrhoeal disease management, direct assessments of mixing a 'safe and effective' solution accurately and other relevant process parameters were evaluated. Comparing several recent ORT intervention projects, the paper concludes that a combination of a commercial approach and mass communication techniques can further ORS use. If a proper incentive system for shopkeepers is installed and message design and ORS product are fully tailored to the perception and preferences of the target population, the commercial availability of ORS will create an extra demand of the product. However, this will not replace distribution of ORS salts delivered free of charge through primary care sources.