A method of cleaning a fouled and/or scaled UF or MF membrane with a solution containing one or more thermo-responsive polymers is disclosed. More specifically, the method comprises: (a) treating the membrane in a membrane separation system with a solution containing one or more TRP, wherein said TRP is soluble in said solution and at least an effective amount of said TRP diffuses into a foulant layer that is present on the surface and/or in pores of said membrane; (b) making insoluble said TRP diffused into said foulant layer; (c) optionally rinsing the membrane; (d) optionally backwashing the membrane with air and/or liquid between the steps (b) and (c); and (e) optionally backwashing the membrane with air and/or liquid after the membrane is rinsed in step (c).