Too embarrassed to take a before picture, I offer the finished product, a shiny clean vent filter for my stove's exhaust fan.
THE PROBLEM: I don't think I'm alone in saying I hate to clean my stove. This time while cleaning under the vent hood, I looked at the metal filter that covers the exhaust fan. Filthy! A quick snap and it was out. Only then was the extent of the greasy grossness apparent.
I heated a kettle of water and ran boiling water through it with no luck. Soaking it in a sink of dish liquid and hot water brought few results until I took an old toothbrush to it. While the brush loosened quite a bit of the accumulated grease, the soap wasn't cutting the grease. Next I tried wiping the edges with a damp paper towel and Ajax. It helped the edges some, but the filter was still embedded with grease. All the while I kept pouring boiling water through it. Still no luck.
HINT: Use tongs to lift the filter from the boiling water.
AT LAST, THE SOLUTION: I emptied all the water from the sink, laid the still damp filter flat and sprinkled a good layer of automatic dish detergent on the surface. Next I poured another kettle of boiling water over it and let it sit. Within 2 minutes the water was brown, within 5 minutes the metal shown through. I emptied the sink and loosened particles with a toothbrush under a stream of warm warm while another kettle boiled. Then I repeated the process. In 5 minutes, the filter was aluminum bright, almost new. Left to air dry, it went back in with ease.
DON'T FORGET: All the grease going down the drain is not good. Poor several TBSP of baking soda in the drain, then add 1/2 a cup of vinegar. It will bubble like one of those old school project volcanoes, sure, but it cuts the grease, cleans the drain and eliminates odors.