We have one we used all summer. You're talking about the metal slats that are close together behind the filter? Warm soap and water. You can also hose down the outside. My husband takes it out puts it at an angle after washing it and uses a leaf blower to dry it and push anything left out. We also use those cans of air "condensed air" along the slats if we're not going to clean it completely. And yes they all get that smell. It's actually pretty normal.
Uh... at this point you're too worried about it. I would get rid of it and buy a new one next year from walmart for 100 bucks. That will save you time worry and whatever else.