Purification of the Church is frequently invoked to narrate Protestant justifications for the break from Rome during the Reformation. It also functions to link the Reformation to a process of modern disenchantment. However, little attention has been paid to the rhetoric of pollution and precisely how the reformers articulated the dangers of polluted ritual. The historical location of the sources examined here is the middle decades of the 16th century when Protestants were dealing with political setbacks to the Reformation cause in the Holy Roman Empire, particularly the imposition of the Augsburg Interim by Charles V. This law was designed to find some middle ground between Catholics and Protestants until the schism would be settled at the Council of Trent. However, the debates about whether certain ceremonies, supposedly non-binding with respect to doctrinal commitments, could be used for politically expedient purposes, pushed Protestant thinkers to reassess the power and dangers of liturgical practices and paraphernalia. This article interprets the discourse of pollution in Protestant controversies about compromise in ritual matters by treating the responses of two theologians writing against the Interim from different parts of Germany: Joachim Westphal and Wolfgang Musculus. By laying out the causes of ritual pollution and its negative effects upon body and soul according to individuals who worked for reform in both their intellectual activity as well as their pastoral service, this article demonstrates the importance of ritual matters for Protestant moral thought.