+1 on the AVR. Mine has been serviced, so I don't mind pulling the chassis cover and hitting it with compressed air. My rack doesn't have doors, so between my 3kids and cat, the dust flies! I dust and clean my gear weekly.I think you just have to keep dusting them off. You might be able to set them up in a clean room with negative air flow, but this probably would cost you more than it is worth. I worry more about dust getting into my amps and receiver.