That looks like the paint is chipped to me or maybe I am blind, I would touch that up so it dont get worse.

 

Talcum powder or cornstarch will do the same thing... Saw it the other night on the TV program, "American Restoration..."

 

Well that sucks.

 

Wow the flour is a trick I never heard of...Sounds logical like a real low abrasive dry compund..I like...I already see the baking flour out and a leaf blower out in the driveway. After that flour mess the leaf blower will come in handy getting the flour out of tight spots. I would definitely wrap my air cleaner with a large zip lock bag and rubber band too while that flour is flying around