The Macbeth effect is a metaphorical association between physical and moral cleanliness - transgression of one’s morality leads to increased desire to clean oneself (Zhong & Liljenquist, 2006). Earlier studies examined psychological associations between bodily and moral purity according to controlled processes, such as rating product desirability. The influence of the Macbeth effect on more automatic processes (stimuli processing speed) was explored in three studies. We examined whether thinking about one’s moral transgression (Studies 1 and 3) or others’ immoral behavior (Study 2) contributed to slower reaction times (RTs) to stimuli related to physical purification. It seems that automatic processes may also be affected by the metaphor “morality is purity”: It is manifested in slower RTs to stimuli associated with bodily cleansing when recalling one’s own past transgressions (Study 3) and in slower responses to words connected with purification of the external world while recalling immoral behaviors of others (Study 2).