If vodka isn't working, then what has happened is that oil penetrated the metal of your atty (I realized that my previous post wasn't clear, sorry). If this is the case, then no amount of alcohol cleaning is going to help you.
So what you need is rubbing COMPOUND - not rubbing alcohol.
It's has the same effect as wet sanding, but with a much finer grit than you could ever get with sand paper.
Since none of your cleaning attempts have worked, further efforts with any type of solvent isn't going to work, unless you use something so strong that you will taste the solvent - which would be worse than your current situation.
From the info you have given, this is what I believe has happened to you:
Your buddy - the one that used his atty in a cloud chasing contest - heated the metal of the atty whilst competing (a normal occurrence during competition).
As a matter of fact, he heated it so much that small irregularities in the metal that would normally be closed/too small could now retain oil, and when the metal cooled, small amounts of the oil were trapped.
Now, every time you heat the atty up during use, it's releasing small amounts of the oil.
So, you can polish it up with rubbing compound, or a coarse polishing agent, or heat the crap outta that thing in an oven (a kiln would be better). If you are going to heat it, make sure to pull any seals (including the center pin grommet), then heat the atty to 450 minimum for a good 45 mins.
This will solve your problem.