NOVELTY - Increasing hydroxide content of polymetal hydrochloride compound comprises subjecting a solution of the compound to electrodialysis.    USE - For increasing hydroxide content of polymetal hydrochloride compound, e.g. aluminum-zirconium chlorohydrate (claimed), as water purification agents, or as binders in catalyst applications.    ADVANTAGE - The method produces enhanced efficacy aluminum antiperspirant salts and enhanced efficacy aluminum-zirconium antiperspirant salts in a more straight forward manner than the currently utilized process. It produces aluminum and aluminum-zirconium antiperspirant salt compositions that do not require the use of aluminum metal.    DETAILED DESCRIPTION - Increasing hydroxide content of compounds of formula Mm(OH)nXam-n (I), where M is a metal present in MmXam (II) that undergoes a reversible reaction with water, producing compound (I) and hydrogen, comprises subjecting a solution of Compound (I) to electrodialysis conditions to generate HX, or subjecting a solution of Compound (II) to electrodialysis, where Compound (II) subsequently hydrolyzes to form Compound (I) with generation of HX, such that the hydroxide content of Compound (I) is increased relative to the hydroxide content of the initial Compound (I).    M=metal;    a=valence of the metal ion;    X=anion;    n=lesser than 0 but less than or equal toam; and    m= approximately 1.    INDEPENDENT CLAIMS are included for:    (1) a polyaluminum halide (PAH) comprising aluminum, hydroxide, and a halide, where when analyzed by HPLC, the PAH exhibits a peak area of peak 5 of greater than 50% and or a combined peak area of peak 5 and peak 4 of greater than or equal to 70%;    (2) an antiperspirant composition comprising a carrier, and PAH; and    (3) an aluminum-zirconium halohydrate comprising aluminum, zirconium, hydroxide, and halide; where when analyzed by HPLC, the aluminum-zirconium halohydrate exhibits an HPLC peak 5 area of greater than or equal to 80% and an HPLC peak4 -3 ratio of less than 0.15.    DESCRIPTION OF DRAWING(S) - The figure shows an HPLC analysis of aluminum-zirconium tetrachlorohydrate-glycine.