1 Just dip a cotton ball in tea tree essential oil and dab it on the affected area. 2  Rinse your face after 15 to 20 minutes. 3  Another option is to mix a few drops of tea tree oil in 1 tablespoon of aloe vera gel. 4  Apply it on your pimples and blemishes, leave it on for 20 minutes and then rinse it off. Rinse your face after 15 to 20 minutes. 2  Another option is to mix a few drops of tea tree oil in 1 tablespoon of aloe vera gel. 3  Apply it on your pimples and blemishes, leave it on for 20 minutes and then rinse it off.