Lack of access to clean water is among the most pressing environmental problems in developing countries, where diarrheal disease kills nearly 700,000 children per year. While inexpensive and effective practices such as chlorination and hand washing with soap exist, efforts to motivate their use by emphasizing health benefits have seen only limited success. This paper measures the effect of messages appealing to negative emotions (disgust at consumption of human feces) and social pressure (shame at being seen consuming human feces) on hand-washing behavior and use of and willingness to pay for water chlorination among residents of slum compounds in Dhaka, Bangladesh. Neither the traditional, health-based message nor the new disgust-and-shame message led to high levels of chlorination during a free trial, nor to high willingness to pay for the chlorine at the end of the free trial. Provision of low-cost hand-washing facilities did increase hand washing, although the effect size is modest.