I agree, remove the discs, park the parts then reassemble with the same number of discs after you clean them with a clean rag. Be sure they sit in there squarely and not cocked so they don't crush. A light coat of oil (couple of drops) on the plug threads is advised
Be sure to clean out the hole that the spring and detent recess into an careful not to crimp the small spring that holds the detent for the plug. Use a small pic to depress the detent until the plug passes over it then torque the plug back in tight.