So...true confession. I have never used an alum block post shave. I know some guys still use one but it seems this shaving habit is not common (the poll will tell the tale). As I understand it, an alum block post shave serves as an antiseptic, astringent, styptic. I also understand it stings like heck if you have razor burn....so it can act as a barometer for your shave. So...do you use an alum block post shave? If so, why?