A method (and concomitant kit) for treating a surface to reduce subsequent 137Cs nuclide desorption comprising contacting the surface with a first cation-containing solution, the cation being one or more of Cs+, Rb+, Ag+, Tl+, K+, and NH4+, and contacting the surface with a second cation-containing solution, the cation being one or more of Cs+, Rb+, Ag+, Tl+, K+, and NH4+, thereby reducing amounts of radioactive cesium embedded in clays found on the surface.