Provided is method of treating a collection of resin beads (a) comprising the steps of (a) providing the collection of resin beads (a), wherein the resin beads (a) comprise one or more vinyl polymers having quaternary ammonium groups; wherein 90 mole % or more of the quaternary ammonium groups are each associated with a chloride anion; (b) bringing the collection of resin beads (a) into contact with an aqueous solution (b) comprising one or more dissolved (M)nXq to form a mixture (b), (c) separating water and compounds dissolved in the water from the mixture (b), to form resin beads (c) and waste solution (bw); (d) bringing resin beads (c) into contact with an aqueous solution (c) comprising dissolved (M3)(OH)p, to form a mixture (d).