Well Vanish spray worked on our carpet for 5 greese marks it was old greese too. Only trouble was that those patches are now too clean compared to the rest of the carpet!
A mate told me about the white wine trick and I've sucessfully used it on many occasions to remove red wine stains from the carpet and from my upholstered furniture only tried it when the stain is wet not sure if would work if the red wine stain has dried