Crystallise etiocholane from acetone. The method of purification for 5-androstane (above) could be used here. [Shoppee Helv Chim Acta 27 246, 260 1944, Butenandt & Dannerbaum Hoppe Seyler's Z Physiol Chem 229 192 1934, Beilstein 5 III 1110, 5 IV 1211.]
