A method according to claim 1 wherein the composition further comprises an effective amount of a carbonate of the formula XHCO3 or, a phosphate of the formula Xa Hb PO4, where a+b=3 and a or b can be 0, Xa Hb P2 O7 where a+b=4 and a or b can be 0, or Xa Hb P3 O10 where a+b=5 and a or b can be 0, and where X is an alkali metal or ammonium.