Coarsely chop freshly dried calendula flowers in a blender or electric coffee grinder. Transfer them to a widemouthed jar and add enough olive oil to cover. Cover the jar and let the mixture stand for two weeks. (If you are in a hurry, you may substitute vegetable oil for the olive oil and heat the mixture in a slow cooker set on the very lowest setting for four hours or overnight. Check the mixture occasionally so that it doesn’t burn.)
Pour the oil through a strainer lined with muslin or cheesecloth. Add one to four parts melted beeswax (depending upon stiffness desired) to ten parts of the strained oil to make a creamy salve, or omit the beeswax and use the oil as a liniment. You may add a few drops of tincture of benzoin to either the salve or the liniment as a preservative.
Store the salve in a small widemouthed jar. It will keep for about a year unrefrigerated.