The Ironsand Skin Toughening Method requires one to dig a deep pit and bury rough ironsand around it. After ingesting a dose of Medicinal Powder and applying a certain medicinal lotion externally, one would strike against the ironsand surrounding the pit, hammering the skin membrane.
When first practicing this technique, the skin membrane is easily damaged, leaving bloodstains. An additional dose of Qi and Blood Powder is necessary. After repeated practice, the skin gradually heals until one can freely collide with and scrape against the ironsand in the pit without any damage to the skin membrane, eventually mastering the technique.
"It's indeed much cruder compared to the Golden Jade Skin Toughening Technique,"
Chen Mu thought to himself.