UPDATE: So I tried this out yesterday: the solution foamed up and clogged the spray nozzle so I couldn't spray it. My next move was to put the H2O2 in the spray bottle by itself and sprinkle the baking soda on top. That worked great! I still have a little ring from the stain by the odor is gone! (How to remove urine stains from a mattress)
How to Clean Window Tracks: white vinegar and baking soda (or hydrogen peroxide!) 30 Q-tips toothbrush hot water paper towels Sprinkle baking soda into the corners, then pour in some vinegar. The baking soda will begin to bubble and loosen up the cruddy stuff. When the bubbling calms down, begin to make circle motions with a Q-tip, then go back into the corners and sweep the muck towards the middle. Pour warm water from the corner to the center. Use your paper towels to wipe everything dry.