I've been using homemade oils for years both for trapping and fishing. Get yourself a big pickle jar and fill it half way with catfish heads,skins or even small whole bullhead catfish work great. Next put enough water in the jar to barely cover the fish. Cover the top of the jar with cheese cloth or some old panty hose. Take the jar lid and poke several holes in it and screw it on over the cheese cloth.( the cheese cloth is to keep the fly's out) Set the jar on top of your shed or somewhere were it won't get disturbed.In about 4-6 weeks the fish rots down and all the oil comes to the top. You can either just pour the oil off or use an injector needle to extract the oil off the top. Use the oil as a dip bait or sponge bait. I like taking a small bullhead and sewing a dipped piece of sponge into the belly cavity. You can make your own oils from most anything using this method like shad,crayfish,shrimp etc..,and they are much more pure and effective then commerial oils.