Tea tree oil has antiseptic as well as antifungal properties that help a lot in the treatment of toenail fungus. This oil is also used to treat other kinds of skin infections. Mix a few drops of tea tree oil in one teaspoon of olive oil or coconut oil. Use a cotton ball to apply the mixture on the affected toenail. Leave it on for 10 minutes, and then use a toothbrush to gently scrub the affected nail. Do this two or three times daily until you are satisfied with the results.