A method for preparing an aqueous composition, comprising the steps of: a) dissolving boric acid in a solvent including a compound selected from the group consisting of glycerol, glycols, glycol derivatives, and any mixtures thereof; and b) mixing the boric acid solution obtained in step a) with an aqueous solution including from 1.0 to 50 weight % of phosphoric acid. The present application also provides an aqueous composition including water, from 1.0 to 50 weight % of phosphoric acid from 0.5 to 5.0 wt % of boric acid, and from 2.0 to 20 wt % of a compound selected from the group consisting of glycerol, glycols, glycol derivatives, and any mixtures thereof.