The formalisation of defeasible reasoning in automated systems is becoming increasingly important. Description Logics (DLs) are nowadays the main logical formalism in the field of formal ontologies. Our focus in this paper is to devise a practical implementation for prior work that formalises a version of Rational Closure (an important type of defeasible reasoning) for DLs.We show that the conclusions drawn from it are generally intuitive and desirable. Moreover, we present experimental results showing that using Rational Closure for ontologies of reasonable size is practical.