A method of dry cleaning in which an oil-soluble reagent such as petroleum sulphonate is added to the solvent so that a significant amount of water can be added to obtain a substantially clear dispersion of water in the solvent. In a high-charged system the concentration of added reagent, a so-called detergent is 4% while, in a low-charged system the concentration ranges from ¾% to 2%
Textile Resource (http://www.textile.org.uk)