Effect of grease on the Macbook's wrist rest area

My macbook was bought in September. No yellow stain appears around wrist rest area. That might be due to my cleaning habit. However, I was disturbed by another problem which is slowly causing the effect of grease on the wrist rest area as well as the button. If observing this area facing lights, facula spot can be easily found. My understand is the surface of macbook is not smooth, continuous friction between palm (wrist) and the pad smoothens this area over time.

I'm afraid Apple won't change the cover which is outworn by natural use. Obviously, neither this facula spot can be cleaned off by any mean. I've started to put a small towel on the wrist rest area when using Macbook to avoid it getting worse. Even though this problem is not quite obvious, I really want my Macbook to keep fresh looking and not to be marked by age signs. Have to admit that the effect of grease is common for all laptops, same for my last HP pavilion. The point is, does any MB user have brilliant idea to deal with this effect?