Use vinegar to remove accumulated dirt and grime from the tracks of your shower doors. Fill the tracks with about 2 cups full-strength white vinegar and let it sit for three to five hours. (If the tracks are really dirty, heat the vinegar in a glass container for 30 seconds in your microwave first.) Then pour some hot water over the track to flush away the gunk. You may need to use a small scrub brush, or even a recycled toothbrush, to get up tough stains.