N-halamine chemistry has been an important research topic in these laboratories for over two decades, offering many exciting opportunities both from practical and pedagogical points of view. One of these opportunities is in the use of polymer- and silica gel-bound N-halamines as selective oxidizing agents for organosulfur compounds. In this study, they have been employed to selectively oxidize organic sulfides including dimethyl sulfide and chloroethyl ethyl sulfide, the chemical mustard stimulant. The latter oxidation produced the less toxic sulfoxide derivative with about 70% conversion, with no sulfone produced, and only about 30% accompanying conversion to sulfoxide hydrolysis products. In this article, we report a combination of experimental and computational results.