Calendula has been widely used for skin rashes since the 12th century. Calendula has antiviral, anti-inflammatory and antibacterial compounds that help the body destroy harmful bacteria causing skin rashes. Both the essential oil and the actual herb can be used. If using the essential oil, add two drops to a cup of clean water and mix well. Alternatively, you can add two teaspoons of the finely chopped petals to a cup of clean water. Bring to the boil and simmer for about 10 minutes, then allow to cool. Strain through a piece of clean cheese cloth and reserve the liquid. Dip a cotton ball, or a clean, soft cloth, into either mixture and apply to the affected skin. Repeat every three to four hours.