I do agree with Mr. Ed. Figure how much oil comes from a boat motor being dispersed in the water, also most scents have some kind of an oil base in it to adhere to the bait. I once heard that WD-40 has a shark oil base which is one of the best moisture preventers, Prep-H ointment also has shark oil in it and thats why it is used for an attractant.
But I must go along with FF also, there are a ton of other scents out on the market that are made directly for the purpose. I generally like to use the Crawdad Nitro gravy,squirt it into my tube jigs and it works great, pike love it, just don't get any on your hands or boat....LOL....hard to get the smell out plus the wife will think twice about sleepin with ya for a couple days. I always carry rubber gloves now. ;D