This paper describes successful use of nanostructured birnessite thin films as electrode to remediate aqueous solutions containing methylene blue, which can be a model molecule of phenothiazines largely used in industries. Such electrodeposited thin films, noted HB1, can spontaneously degrade dye, but the reactivity is limited by organic molecules sorption. The use as electrode improves largely efficiency for total discoloring in very soft conditions with very low energy inputs, even at high concentrations. The discolored solutions analyses by ion chromatography report the significant presence of non-toxic small organic compounds and inorganic ions confirming the degradation. Characterization of materials by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Raman spectroscopy confirm that no organic compound were adsorbed onto surface, with no modification of birnessite due to an efficient regeneration by electrochemistry in continuous. For better understanding reactions in real time, in situ measurements by UV–Visible spectroscopy were performed on solution confirming the real interest of coupling to electrochemistry. In complement, another type of sample with lower birnessite amount, noted HB4, was tested with success. These HB1 and HB4 samples used as electrodes present high degradation capacities towards methylene blue equal to 934 mg g−1 of HB1 and 2222 mg g−1 of HB4, without any modification of material. These results are very promising for future eco-friendly applications due to good efficiencies, very simple conditions, without toxic products and wastes, and with low energy needs, both for synthesis and depollution processes.