The three-stage technology for the production of fatty acids from a 50/50 mixture of cottonseed and sunflower soapstocks has been developed. The primary objective of the study presented in this article is to determine the optimal concentration, quantity, and duration of washing with an electrolyte—specifically, a sodium chloride solution—required for the effective separation of the aqueous and oily phases of the carbonate-saponified mass subsequently treated with a caustic soda solution.The research findings demonstrate that, for efficient separation of the soapstock mass from the aqueous phase, washing with a 20% sodium chloride solution at 50% of the total mass after both processing stages significantly enhances the intensity of accompanying substance removal, compared to the theoretically calculated electrolyte concentration of 5.83%.