Thanks everybody, I'll look for the wipes next time I buy pet food. It's not bothering the cat, but it bothers me. She's pure white, and lloks so scraggly with her fur in a mess. fortunately Misty is shortfurred or I would likely be dealing with mats out of this, and I really don't like cutting fur too close to delicate ear flaps.
Hazel, if something works well on the grease, I'll let you know.
Hmmm, they use Dawn on oil-spill effected wild life, maybe I should try it on my greasy (oil-like) cat, and just rinse really well.
That's probably overkill. I'll try the wipes first.