Liquid Metal Dealloying (LMD) is tested to enhance the near-surface magnetic properties of ferromagnetic Iron-Cobalt alloys. With a lower surface electrical conductivity, treated specimens are expected to accommodate the frequency effect better and exhibit a lower level of magnetic loss. This work focuses on the magnetic viability of LMD-treated samples. The magnetic hysteresis cycles of virgin, fully-dealloyed, and partially-dealloyed specimens are measured from quasi-static to dynamic regimes. For each category of specimens, experimental results are compared with numerical predictions given by dedicated hysteresis models. The simulation parameters of the fully-dealloyed and the virgin specimens are leveraged to predict the partially-dealloyed specimen’s behavior and estimate the thickness of the treated area accurately and non-destructively. Together with SEM observations and finite element simulations, these results show that the magnetic behavior of the metallic part in the dealloyed layer is barely affected by the specimen porosity, but the average variations observed experimentally are primarily due to the distortion of the magnetic lines and changes in the local geometry.