A vacuum cleaner with a soft brush attachment will get surface dust. If you have anything inside the honeycomb (or cells), that same vacuum attachment will work. Place the suction over the spot and drag to the right or left. Spot clean with mild soap and soft sponge. Do not rub or fabric can pill. Heavy cleaning can be done in a bath tub but do not submerge the top rail. Dip and swish the extended fabric, remove from tub, towel dry and then hang (fully extended) back in the window to let air dry.