Warning, THIS ADVICE IS FROM EXPERIANCES IN THE 70'* and 80'*, NOT SURE IF IT STILL APPLIES TODAY!!!
My dad had a detail / clean up shop for 20 years, and the one product that worked for us on cloth when all else failed was laquer thinner on a clean white towel. Just wipe it back anf forth. We use to tell the customers it was "dry cleaning solution". Do not touch any plastic or it WILL stain.
I CAN-NOT GUARANTEE THIS!!! I can just say it always worked for me. Make sure you test the thinner on the fabric in an inconspicous area first. Also, do it outside with the windows rolled down or you will get a nasty headach, If not worse.
To clean tan seatbelts after we accidently sprayed them with black rust proofing, we would spray the thinner from the back-side while holding a vacuume to the soiled side. I know thinner is explosive, but we didn't have any problems. We never had a seat belt that we could not remove the entire stain.
Good luck! And sorry for the spelling errors.