Stuck on grease is usually a sticky goo-ish type substance that is best dealt with by using a soapy kind of cleanser- namely a degreaser along the lines of 409- and a heavy duty nylon scrubbing pad.
A warning however:
Depending on how heavy the build-up is, it usually requires a little bit of elbow grease to get rid of it. The problem with that is you have to be careful not to ruin the finish of whatever that build-up has latched itself onto. If you're not concerned about the surface, scrub away with a heavy duty nylon pad and degreaser. If the surface is a concern, forgo the scrubbing pad. Spray the area with degreaser (testing a small patch for colorfastness first) and clean with a rag dipped in the hottest water possible. (Gloves may be a good idea here.) Wring out your rag in fresh hot water often- and change rags when necessary.
If the build up is really, really heavy, soak the area in degreaser and scrape off the build-up with a putty knife. Then use the heavy duty scrubbing pad and/or the 'hot rag' method.