Thanks for your comment Rob.
To my mind, the effectiveness of positive messages around status, convenience and aesthetics has more to do with the 'instant' nature of these benefits. Getting a toilet immediately provides these benefits. Also, from a behavioural economics standpoint, a gain in the short term is valued more over a potential loss (in health) in the long term. The health argument does not resonate very much with the users because the effect is cumulative and manifests over time. The psychological draw then is for gratification in the now. More importantly, however, these positive benefits of getting a toilet do not always translate into toilet use - and a loss argument might be effective there. This also bears out that the consumers mostly see sanitation as a private good (privacy, convenience, status appeals) versus a public good (health).