A cosmetic agent for treating a keratinous material, wherein the cosmetic agent is a fluid and comprises a) at least one organosilicon compound, wherein the at least one organosilicon compound contains a compound of formula and at least one organosilicon compound of formula, where, in the organosilicon compound of formula, R 1 R 2 N-L-Si(OR 3) a (R 4) b, - R 1 and R 2 both represent a hydrogen atom, - L represents a linear, divalent C 1 -C 6 alkylene group, preferably a propylene group (-CH 2 -CH 2 -CH 2 -) or an ethylene group (-CH 2 -CH 2 -), - R 3 and R 4 independently represent a methyl group or an ethyl group, - a represents the number 3, and - b represents the number 0, and where, in the organosilicon compound of formula, R 9 Si(OR 10) k (R 11) m, - R 9 represents a C 1 -C 12 alkyl group, - R 10 represents a hydrogen atom or a C 1 -C 6 alkyl group, - R 11 represents a C 1 -C 6 alkyl group, and - k represents an integer from 1 to 3, and - m represents the integer 3 - k, and b) at least one multivalent metal cation comprising lanthanum in the form of lanthanum chloride, in a molar concentration of 0.001 mol/L to 2 mol/L, preferably 0.005 mol/L to 1.5 mol/L, more preferably 0.01 to 1 mol/L, most preferably 0.02 to 0.5 mol/L. a) at least one organosilicon compound, wherein the at least one organosilicon compound contains a compound of formula and at least one organosilicon compound of formula, where, in the organosilicon compound of formula, R 1 R 2 N-L-Si(OR 3) a (R 4) b, - R 1 and R 2 both represent a hydrogen atom, - L represents a linear, divalent C 1 -C 6 alkylene group, preferably a propylene group (-CH 2 -CH 2 -CH 2 -) or an ethylene group (-CH 2 -CH 2 -), - R 3 and R 4 independently represent a methyl group or an ethyl group, - a represents the number 3, and - b represents the number 0, and where, in the organosilicon compound of formula, R 9 Si(OR 10) k (R 11) m, - R 9 represents a C 1 -C 12 alkyl group, - R 10 represents a hydrogen atom or a C 1 -C 6 alkyl group, - R 11 represents a C 1 -C 6 alkyl group, and - k represents an integer from 1 to 3, and - m represents the integer 3 - k, and where, in the organosilicon compound of formula, R 1 R 2 N-L-Si(OR 3) a (R 4) b, - R 1 and R 2 both represent a hydrogen atom, - L represents a linear, divalent C 1 -C 6 alkylene group, preferably a propylene group (-CH 2 -CH 2 -CH 2 -) or an ethylene group (-CH 2 -CH 2 -), - R 3 and R 4 independently represent a methyl group or an ethyl group, - a represents the number 3, and - b represents the number 0, and - R 1 and R 2 both represent a hydrogen atom, - L represents a linear, divalent C 1 -C 6 alkylene group, preferably a propylene group (-CH 2 -CH 2 -CH 2 -) or an ethylene group (-CH 2 -CH 2 -), - R 3 and R 4 independently represent a methyl group or an ethyl group, - a represents the number 3, and - b represents the number 0, and where, in the organosilicon compound of formula, R 9 Si(OR 10) k (R 11) m, - R 9 represents a C 1 -C 12 alkyl group, - R 10 represents a hydrogen atom or a C 1 -C 6 alkyl group, - R 11 represents a C 1 -C 6 alkyl group, and - k represents an integer from 1 to 3, and - m represents the integer 3 - k, and - R 9 represents a C 1 -C 12 alkyl group, - R 10 represents a hydrogen atom or a C 1 -C 6 alkyl group, - R 11 represents a C 1 -C 6 alkyl group, and - k represents an integer from 1 to 3, and - m represents the integer 3 - k, and b) at least one multivalent metal cation comprising lanthanum in the form of lanthanum chloride, in a molar concentration of 0.001 mol/L to 2 mol/L, preferably 0.005 mol/L to 1.5 mol/L, more preferably 0.01 to 1 mol/L, most preferably 0.02 to 0.5 mol/L.