Suggestions how to clean this radiator

[rado84]

The radiator is CM Hyper T4 and for the moment it's ok but the dust is slowly gathering and at some point it will start heating up my CPU instead of cooling it. I tried using a soft hair paint brush but it's no good - there's no paint brush with that long hair; the dust is between the plates and is unreachable. I also tried with a vacuum cleaner but it was no good either - the dust won't move at all. I ran out of ideas what to try to get the dust ouf there.