Combine the butters, beeswax pellets, and coconut oil in the top of the double boiler or in a mason jar sitting on a washcloth in a small saucepan.
Put about an inch of water in the bottom of the double boiler or in the saucepan and bring to a boil.
Reduce heat to simmer and stir the mixture carefully until all the ingredients have melted. NOTE: Be careful not to get any water in to the butters/oil mixture as it will ruin the bars.
Once all ingredients have melted, remove them from the heat.
Stir in essential oils.
Quickly and carefully pour into the plastic deodorant molds. If possible, transfer to the refrigerator to harden or let sit on the counter for 4-6 hours or until completely cooled.
Important: When finished, do not put the pan or jar directly into the sink or attempt to wash as you would regular dishes. Wipe out the double boiler or pan as much as possible with paper towels, old newspaper, or rags that can be thrown away and then wash in hot soapy water as soon as possible.