For the simplest filament cleaner to remove dust etc.
Wind a pipe cleaner around a piece of wire (about 3mm wire) to make a spring shape, then slide it off the wire.
Feed your filament through the center of the spring shaped pipe cleaner.
Pipe cleaners are cheap and can be purchased from any tobacconist and some supermarkets.
Note : Tripod.stl is a reel hub holder for a CTC printer, I only put it here because thingiverse would not allow this post without a part file.