Plasma simulation is getting increasingly important to reproduce technically relevant configurations in electrical engineering. For instance, simulation tools are used to represent the evolution of partial discharges in internal defects such as voids and electrical treeing. In these cases the simulation includes both the gaseous defect and the polymeric bulk where the defect is embedded. A major role is played by the physical characteristics of the surface separating the defect from the bulk and, among these parameters, the surface conductivity is one of the most important aspects. The latter may take very high values due to the cumulative interaction of dielectric materials with a large number of partial discharges.The simulation of configurations involving high surface conductivities is particularly tough since, as we will show, this may reduce the maximum time step increase of simulation algorithms. In this work, we introduce a proper numerical filter that can circumvent this problem and we show that, using this technique, we can significantly enhance the performances of simulation algorithms without compromising their accuracy. The performances of this approach will be shown in a set of numerical examples.