6 months rest, now clutch is slipping
 

Let my RX sit for 6 months (due to health issues), I know it's bad for these cars... but went on a drive this evening to find the clutch slipping all over the place. This when it did not slip at all when it was driven last. The only thing I can think of was when I added oil to the engine, about a tablespoon missed the mark. Could this stray oil have made its way into the clutch somehow causing this problem. Or is there some other principle at work here?

Check the inspection plate to see if you can see oil on the flywheel

looks like that is where the oil went. What to do now? Is it safe to spray brake parts cleaner in there to clean off the oil and get it dry and grabby again?