Parkinson finish is a lot like your skin. When its dry, you notice scratches easier then when its moist. Sounds like your getting some oil soaked in. Keep doing what your doing and you should be good to go.
Endowment Lifetime NRA Member, Certified CCW/Pistol instructor.
"To preserve liberty, it is essential that the whole body of the people always possess arms, and be taught alike, especially when young, how to use them". Richard Henry Lee 1788