The electropolishing regime of heavily doped p-type silicon electrodes in aqueous HF solutions is investigated using a rotating disk electrode. Analysis of the current dependence on rotation speed leads us to conclude that the current is only limited by the oxide layer present at the silicon surface. There is no influence of a viscous layer as in true electropolishing. The oxide is characterized by simultaneous in situ capacitance and transient current measurements during its dissolution in the electrolyte under a controlled potential. The results are compared to those obtained with well-defined thermal and anodic oxides during their dissolution in the same conditions. It is shown that the fast dissolution rate of the electropolishing oxide layer depends on the formation potential, and that it determines the shape of the i-V characteristics.