1 You can externally apply plain yogurt on the affected skin area and let it sit for at least 20 to 30 minutes, or preferebly overnight. 2  This will help relieve the itching sensation. 3  For a vaginal yeast infection, dip a tampon in yogurt and then insert it in the vagina for two hours. 4  Do this twice a day. Apply it on the affected skin area to control the growth of the infection. 2  In case of oral thrush, swish the oil in your mouth for five to 10 minutes. 3  You can also add a few drops of tea tree oil or cinnamon oil and then use. 4  Do not swallow.