An alum block is used after shaving for cleaning the skin. The block is made from potassium alum and is a natural antiseptic and deodorant. Alum blocks were used by the ancient Egyptians over 4000 years ago. Also popular in Turkish barber shops today.
To use, simply wet your skin and the block with cool water and rub the block over your face, legs, arms etc. Leave on for around 1 minute, then rinse off. You will feel that your skin is free of grease and tighter. After use dry the block as leaving it wet will cause it to dissolve. Drying the block also helps to keep it smooth, so that it can easily glide over the skin next time you use it.
Use every few days to keep your skin in great condition.