A formulation including (A) at least one compound selected from methylglycine diacetate (MGDA) and glutamic acid diacetate (GLDA) and salts thereof, (B) at least one graft copolymer composed of (a) at least one graft base selected from nonionic monosaccharides, disaccharides, oligosaccharides and polysaccharides, and side chains obtainable by grafting on of (b) at least one ethylenically unsaturated mono- or dicarboxylic acid and (c) at least one compound of the general formula (I), where the variables are defined as follows: R1 is selected from methyl and hydrogen, A1 is selected from C2-C4-alkylene, R2 are identical or different and selected from C1-C4-alkyl, X− is selected from halide, mono-C1-C4-alkyl sulfate and sulfate.