Dominant approaches to developing more sustainable ways of living are often underpinned by the modern values and knowledge that have been instrumental in creating our unsustainable world. Such approaches tend to emphasise reducing unsustainability via technological fixes rather than addressing sustainability more comprehensively. This paper argues that more traditional forms of knowledge (associated with deeper ecological, spiritual and ethical values) are important for addressing sustainability more holistically. To demonstrate this, we present and discuss the Miswak Toothbrush designed by the lead author. The Miswak Toothbrush has been designed to appeal to modern teeth cleaning customs but its brush head is made from Miswak, a natural twig that has a long tradition of use for teeth cleaning in rural India. This paper contributes insights into what contemporary product design can learn from traditional knowledge by discussing the implications of the Miswak Toothbrush for the development of a more meaningful and more sustainable material culture.