The clean-up of crude oil is accomplished using an oil solubilizing agent from a class of onium halides to solubilize the oil in water. The oil solubilizing agent includes a quaternary phosphonium halide, a quaternary ammonium halide, or a ternary sulfonium halide. The onium halide also includes a hydrophobic hydrocarbon chain having from 10 to 24 carbon atoms, and can include both aromatic and aliphatic components.