A friend of mine suggested me to use a wet alum stone after shaving. Is this efficient?
It just so happens that Potassium Alum has registered its own domain name! They tout the uses there as:
Potassium alum has been a sought after natural mineral salt for thousands of years due to its abilities to effectively contribute to water purification, pickling, tanning, medical procedures and in cosmetics as an aftershave or deodorant. Additionally, due to its attractive crystal appearance, potassium alum has become a favorite amongst mineral collectors. Potassium alum is antimicrobial and can therefore be used as a natural deodorant by inhibiting the growth of the bacteria responsible for body odor. It is also used in medical procedures as a local astringent and styptic.
So it is efficient in stopping germ grown and constricting the skin to stop bleeding. Generally, after shaving, most men want some sort of relief from "razor burn" after shaving. This is generally caused by the removal of skin along with the hair. Potassium Alum is a type of salt. So throwing this on your face will probably make you forget about the razor burn, and concentrate on the salt burn that your raw skin is now enduring. Of course, this is the same mechanism that many alcohol based after shaves will use (although the mechanisms for providing relief are different).
Alcohol evaporates quickly, causing the surface of the skin to feel cool.
Potassium alum tightens the skin as a dehydrating effect of the salt, and gives a refreshing feeling in that manner. Again, it's more meant as an astringent and styptic though.
Alum is a double salt...and a very good Astringent which precipitates proteins,.. During shaving our skin is exposed to harsh condition..i.e shaving blade rubbing on our skin which damages the skin and open pores which might cause irritation and burning... Thus ALUM being a very good Astringent precipates the proteins which are the constituent of the pores of our skin helps reducing the Burning and soften the skin...they also constricts the open tissues (blood vessels, nerve endings if exposed any....) thus prevent bleeding and give a smooth feel to the skin....
- Using ALUM during summers can also prevent excess sweating and give a good feel to the skin as it blocks the pores on the face...