The capture of engine-borne particulate matter (PM) in after-treatment systems is a complex process. Because of the intrinsic heterogenic nature of the PM, the particles undergo transformations that make it very difficult to isolate their motion and deposition in experiments. In a previous study, a model for hydrocarbons (HC) evaporation of the particles during the capture process was proposed to explain experimental results that showed a significant increase in the capture efficiency when compared to those predicted from theoretical models [J. Sjoblom and H. Strom, Ind. Eng. Chem. Res. 2013, 52, 8373]. In this work, inert NaCl particles were fed to an open substrate (cordierite monolith). It was demonstrated that the capture efficiency can be experimentally observed, isolated from other experimental phenomena and uncertainties, if the particles are truly inert. Consequently, the previously proposed model for HC evaporation is a valid starting point for development of comprehensive models for PM motion and transformations.