M.H.
Hi L.,
Be careful with the chemical de-greasers like Dawn, Goo-gone and the like. Even though some say they are natural or just petrolatum products there are still dangers. There are some safe solvents on the market but you really have to investigate. I know Sol-u-mel is completely safe and will do the job on the first try but it can only be ordered through a Melaleuca membership club. I know this for sure because I am a member and would be glad to give you more details.
Stubby's answer is the safest of those reccommended. It may take some work but the Vaseline needs to come out quickly. Just because it is sold in the stores, don't assume that vaseline is safe. Good luck to you!
M.