Oils are used these days in Hoodoo for their expediency. They are carriers of magical intent. Each drop a liquid mojo bag. The oils you come across in Hoodoo are referred to as condition oils, this is because they are used to treat certain specific conditions.
A small quantity of oil goes an amazingly long way. Oils can be used to dress candles, dress objects ( shoes, wallets), for annointing, for altar work, to make up a condition powder etc, etc. Oils are probably the most