I have used a disc sander to resurface a flywheel with less that 50,000 miles on it in order to break the glaze and had good results. You should do that when you replace the clutch disc. If there are grooves or damage to the flywheel surface resulting from a exploding clutch disc, it should be taken to a machine shop and resurfaced.
If you don't pull the engine and fix the rear main seal, this will be a recurring problem and will only get worse. It is rear main seal if oil is getting inside the bell housing and onto the clutch. A leaking oil pan gasket would not leak into the bell housing.