Preferably, the fractal particles are fumed alumina, fumed silica, fumed titania, or combinationsOptionally, electrolytes such as sodium chloride may be added in amounts ranging from about 0-5%, preferably from about 0.5-2%.The compositions of the invention further typically contain an amount of a pH adjusting agent to provide the desired pH of the composition, e.g., the pH at which the fractal pa