The traditional Chinese medicine clear alum you mentioned should be soap alum, which is a mineral product, also called soap alum and melanterite. It tastes sour and cool, and enters the liver, spleen and large intestine. Has the effects of detoxicating, anticancer, nourishing blood, killing insects, astringing and relieving swelling. It can be used for treating spleen deficiency, yellow swelling, laryngeal wind swelling, red eyes and rotten eyes, malaria vomiting (shaoyin malaria), menstrual bloody stool, metrorrhagia, abdominal stagnation, fire injury in soup, infantile sarcoidosis, onychomycosis, blood deficiency and various sores.