LOL i'm not advocating to not run an air filter. Did you not read my entire post? Damage can be done if you get sand and dirt in the engine. But to think a few pieces of dust will ruin your mill is absurd. My point is oil the inner filter, keep the outter one dry and be done with it. Or oil them both, it makes no difference. You'll just need to clean the outter filter or change it more often.