We can finally say that our recommendation is ethanol treatment, as it was a result that the penetration around 48 hours with ethanol treatment may be better than nothing. However, it seems that there is no problem with the way we used to do so by dipping in medium without this ethanol treatment.
At this point, we have not confirmed the effect of ultrasonic waves on the filter pores yet, and we have not confirmed the presence of tears in the filter pore due to vibration, so we decided that we could not recommend it.
