Bay Rum is prescribed in older hoodoo spells for cleansing purposes. It's been largely replaced by Florida Water in modern use, but for those who want to keep up tradition, here's a genuine old-time recipe for how to make your own:
4 ounces Jamaica rum
16 ounces rectified spirits (190 proof alcohol)
12 ounces water
1/4 ounce bay essential oil or laurel leaf essential oil
Note that originally bay rum was made from pimenta racemosa, but there was a lot of confusion over this and the bay laurel plant, as well as plants of the myrica genus from which bayberry come. Consequently, many 19th century recipes are actually made from the more common bay laurel -- therefore, you can use either pimenta racemosa or laurus nobilis to happy effect for this recipe.
Alternately, you can buy readymade Bay Rum from a variety of sources. Commercial blends often have additional spices added to enhance the scent. There are cheap brands that run about $6 for 12 ounces and pricy blends that go well over $10 an ounce.