Grate the cocoa butter on the finest side of the grater.
Add the cocoa butter, coconut oil, sesame oil and avocado oil to the container.
Put the container into the microwave safe pan. Fill the pan with water halfway up the sides of the container. Microwave on medium until the cocoa butter has melted. That should be about two to three minutes. Stir every 30 seconds with the whisk. How long the cocoa butter takes to melt depends on the power of your oven.
Add the essential oils one drop at a time, whisking after every addition. A lightly fragranced body butter would need 3 drops each of lemon, grapefruit and orange oil. Increase the drops until the scent satisfies you, omit if you prefer, or use another scent as you like.
Let the mixture cool somewhat so that it is warm but not hot to the touch.
Put the mixture in the blender and pulse for 10 seconds, then blend on high for 60 seconds to fluff up the butter. Store in an airtight container with lid.