Melt the beeswax over low heat in a double boiler or metal measuring cup (with a spout for easy pouring), placed in a pot filled halfway or less with water.
Once melted, add the castor oil and sesame oil, then take off heat.
When slightly cooled, add the brown sugar (or raw cane sugar*), and mix well.
Using a spatula, pour the mixture into the plastic containers, then close and label.
* Brown sugar creates a dark brown scrub, and alternatively, raw cane sugar creates a light brown scrub. Using raw cane sugar provides a slightly more exfoliating scrub, due to the larger granules (this exfoliates the lips on a deeper level).