Su recently had a small cyst surgically removed and the wound got infected. It became red, swollen, and something under her skin in the surrounding area seemed to be getting hard.
For 3 days, twice a day, she spritzed strong acidic water (pH:2.5) in and around the wound for 1-2 minutes. This disinfects the area, killing all bacteria within 30 seconds. Then, she patted the area with a slightly alkaline compress to maintain a neutral pH on her skin.
After just 3 days, the hardness under the skin has totally disappeared, the redness is completely gone, and the incision is healed!