A strip-form toilet cleaning product comprising a width (B), a height (H) and a thickness (S), wherein the ratio between width (B), height (H) and thickness (S) is between 1:1:0.01 and 1:0.1:0.2, a first extruded phase and at least one second extruded phase, wherein at least the contour of a contact surface (4, 4a, 4b) along the center axis (8) takes the form of a sine wave which has an amplitude of A1,O, wherein the ratio of amplitude to width (B) A1,O:B amounts to between 1:10 and 1:25 and the periodic length of the sine wave corresponds to 0.1-1 times the width (B) of the toilet cleaning product.