Here is a goal: how do I clean the tracks in a window

Which way makes more sense to accomplish this goal?
First sprinkle a little baking soda on the worst parts, usually in the corners. Cover baking soda with a little bit of the vinegar. ... Leave it for 5-10 minutes to work its magic. Come back and start working all that gunk towards the center with your toothbrush. Stick all the gunk on a paper towel and throw it away.