Rose geranium oil has a balancing effect on skin — it moderates oil production whether the skin is producing too much or too little, which is unusual and makes it broadly useful. Alongside that it is antibacterial, anti-inflammatory and a mild styptic, meaning it helps small bleeding stop.
The book pairs it with ingrown toenails, and that combination is exactly right. The skin beside an ingrown nail is inflamed, sometimes broken, sometimes bleeding slightly, and prone to infection. Geranium addresses all four at once, gently enough to be used on tender tissue.
It also happens to be one of the pleasantest oils here, which counts for something in a treatment you have to keep up for weeks.
