The interactions of polarized light with an optically active (chiral), multiply scattering medium are investigated using a relatively simple experimental system incorporating polarization modulation and synchronous detection techniques. The polarization properties of diffusely scattered light are studied as a function of scatterer particle concentration, chiral molecule concentration, and detection direction. A newly derived method for simultaneous extraction of the total degree of polarization, and optical rotation of the linearly polarized fraction, is theoretically discussed and experimentally implemented, using optically thick turbid media with the presence of one chiral component. The method requires measurements at several orientations of the analyzing linear polarizer, followed by data fitting to yield the unknown sample polarization properties. The accuracy and robustness of this method in the cases of weak signals and noisy data are superior to previous two-point approaches of data analysis. The measurable polarization preservation on multiple scattering, affected by the chirality and turbidity of the medium and by the detection geometry as described, provides a useful tool with which to probe the properties of multiply scattering media.