In the EC-processing, we must distinguish between the external ECM, where the process energy source (PES) and the current generated determine the removal rate, and the internal ECM, in which the outer PES leads only to the charging of the double layers and the removal process by the occurs discharge of the double layer capacitance (current).
In some article about ECM process combinations, the EC principles are based on the work of Schuster and Kirchner. However, this paper include only the internal ECM (μPECMM - pulsed electrochemical micromachining by double-layer discharge) what is wrong in my opinion.
I think that the combined occurrence of μPECMM and abrasive removal is possible. The effect of μPECMM is then given (positively) when a small working gap increases (removal rate). In front of the abrasive removal an EC removal would be possible, but would have little effect on the surface. Too large work gaps no μPECMM would work, but "only" conventional ECM, which would be sufficient for surface smoothing.