If you are getting oil on the disc, a good heating would vaporize the oil and reduce the lubrication on the disc. My method for cleaning the disc and/or flywheel and pressure plate is to start out in the highest gear of the transmission; get the engine up to 3-4k RPM and slip the clutch while holding the RPM until the car is up to 30 or 40. A couple of applications does a pretty good job of getting rid of shudder and grabbing.
This will sometimes work for a clutch that is dragging to where first engagement is stiff and reverse grinds. After a few 'burns" you can tell the clutch engagement is less crisp but the drag is more manageable.