We present an analysis of the cross-relaxation dynamics between optically polarized Xe-129 and surface C-13 and H-1 spins in methanol adsorbed on a SiO2 surface. Analytical expressions for the C-13 polarization are derived, which show that the C-13 polarization is determined by cross-relaxation with both Xe-129 and H-1 spins. The H-1 spins act as a polarization sink; however, saturation of the protons results in a further increase in signal intensity. Replacing the H-1 spin reservoir with H-2 increases the C-13 Signal by a factor of 12 (25 as compared to room-temperature data). Further improvements are anticipated using higher-powered lasers.