Get yourself a spray can of electrical contact cleaner from Radio Trap/Lowe's/HD. Spray cleaner on minijack and insert into aux port in console. Remove, repeat....Several times. Re-apply the spray every few insertions.
Be sure to spray the chemical outside your car so you don't get it all over your interior. It dries quick and will not damage electronics. Not sure I can say same for leather, etc..
This will work. I've done this on several cars from several manufacturers with 100% good results.
Here's an example so you know what to get.
http://www.amazon.com/CRC-Electrical...ontact+cleaner
Please don't get "creative" and try to substitute another chemical.