Window tracks
There are parts of your house that you probably look at, marvel at the first, but then think “I have no idea how to clean that, so I’ll just leave it.” Window tracks definitely fall into this category with their tiny crevices and cracks, and they’re full of dirt and dust
Step one: get a toothbrush and clean all the dirt you can see. Step two: use a cotton swab to get into the corners. Then, the real trick: take a clean paper towel dipped in vinegar and clean the rest of the window track.