The squirrel cage blades have a unique shape that curve and they collect dirt well. I've never seen a fan so clogged completely. Is there anyway to clean these easily? I tried a vacuum and tooth brush but it's difficult.

The big sticky stuff comes out after much brushing/picking at the blades but they are still a mess. I believe that unless I can really get them clean, air circulation will suffer.

I would love to remove it from the ceiling and get at the fan directly, but it's installed under a fire "door" shroud and I'd have a real mess.

I don't have hi pressure air.

(I assume the dirt is "structurally" sound because of a previous smoker.)