Applying 100 percent tea tree oil to the nails twice a day for six months can cure some instances of nail fungus, according to MedLinePlus. Approximately 18 percent of people who try this method are successful.
In addition to possibly healing nail fungus, tea tree oil may also improve the look of nails and reduce the symptoms of fungus, explains MedLinePlus. After three months of using tea tree oil, more than 50 percent of people saw a difference in the nails. Approximately 60 percent of people saw a noticeable improvement after six months of using tea tree oil. Lower concentrations of tea tree oil are likely ineffective for nail fungus.