The unconventional solution model of Mobile Order, which had previously been shown to provide a very accurate thermodynamic description of anthracene solubilities and chemical potentials in binary hydrocarbon + alcohol solvent mixtures, is extended to binary solvent systems containing two self-associating alcohol co-solvents. Expressions are derived for predicting the solubility of crystalline solutes from a prior knowledge of the solubility in the two pure alcohol solvents. Applications and limitations of the newly derived equations are assessed using anthracene solubilities in binary 2-propanol + 1 -propanol, 1-butanol + 1-propanol, 2-butanol + 1-propanol, 1-octanol + 1-propanol, 1-butanol + 2-propanol, 2-butanol + 2-propanol, and 1-octanol + 2-butanol mixtures which are measured as part of the present study. The two most successful expressions permit each individual alcohol co-solvent to form homogeneous hydrogen-bonded complexes. Both equations predict the experimental anthracene solubilities to within an average absolute deviation of about +2%. Inclusion of terms to account for heterogeneous complex formation between two dissimilar alcohols has little effect on the predicted values.