Mental contamination (MC) refers to feelings of internal dirtiness or moral pollution without direct physical contact. While constructs such as fear of self (FoS), scrupulosity, obsessive beliefs, and inferential confusion (IC) have been linked to MC and the urge to wash, these relationships remain underexplored, especially in experimental and cross-cultural contexts. This experimental cross-cultural study investigated whether MC and MC-specific emotions (MCSE) such as disgust and guilt mediate relationships between cognitive vulnerabilities and urge to wash, with particular emphasis on identifying cultural variations in these psychological processes between Turkish and American populations. This study employed a between-subjects cross-cultural design comparing participants from Turkey (n = 85) and the United States (n = 75). Following completion of baseline measures assessing FoS, scrupulosity, subdimensions of obsessive beliefs, and inferential confusion, participants engaged in a controlled experimental manipulation where they imagined themselves as perpetrators in a non-consensual kissing scenario (MC manipulation). Post-manipulation assessments measured MC, MCSE, and urge to wash responses. Cross-cultural comparisons and serial mediation analyses were conducted using SPSS PROCESS. Analyses revealed distinct mediation patterns between Turkish and American samples. For Turkish participants significant indirect effects of FoS, IC, scrupulosity and obsessive beliefs related to threat, perfectionism, and intolerance of uncertainty on the urge to wash were mediated through MC and MCSE pathways. In contrast, the American sample showed more limited mediation effects, with only obsessive beliefs about threat and importance/control demonstrating significant indirect effects via MC. This experimental cross-cultural investigation demonstrates that MC and MCSE significantly mediate cognitive vulnerabilities' effects on cleansing urges, with markedly stronger mediation pathways in Turkish compared to American participants. These cross-cultural differences highlight the role of culture-specific cognitive mechanisms in MC processing. The study provides the first experimental evidence for cross-cultural variations in MC mechanisms and offers important implications for developing culturally-adapted therapeutic interventions.