Smell is typically considered the least of the senses, the lowest in a hierarchy privileging sight since the Enlightenment. The experience of olfaction is highly emotion-laden and tightly bound to memory and personal history, and Western smell vocabularies are notoriously poor: scentful experience seems poorly suited as a basis to enroll others in political projects, especially in contexts that privilege rational public debate. But smells can also spur us to immediate action. When do they prompt us to enroll others in that action, and how do we turn individual sensory experiences into convincing arguments? How does olfaction leave the realm of individual experience and generate consequential social change? This article shows how social processes of olfaction can be used to prompt social action. With an analysis of the complaints that legitimated the 2015 destruction of a shanty town in southern Sweden and a historical inquiry into the shared beliefs that allowed those complaints to make sense, I show how olfactory claims -claims based on personal experiences of smell -can leverage broadly shared norms, values, and meanings to demand social action. Despite the personal, emotional, and fleeting nature of olfactory experience (or perhaps thanks to those features, which disallow independent confirmation) it can easily be weaponized as a political tool. This article asks how individual sensory experience can have social impact, and shows how a fit between local olfactory cosmologies and the particular features of olfactory claims can allow them to be used to demand action.