Pure olive oil soap - the kind you can buy from Greek merchants. This soap is super mild and yet it take out grease with the best items.

I had years old grease stains on khakis and a t-shirt (clothing had been relegated to 'painting' clothing). I just wet the stain with water, rubbed some olive oil soap on it (its a bar soap), scrubbed the fabric together and then tossed it in with the wash. The stains were gone!!! I repeated the same process with a Cannondale jacket that had old bike grease stains on it (that we'd tried everything on) and it came 100% clean.

We also successfully used it to get bike grease out of ivory wool berber carpet when nothing else would work.

I'm telling you - this stuff is the BOMB.

http://www.elikioliveoil.com/puroloilsoap.html