Wiper blades not only keep rain water off a car's windshield, they also help provide a clear viewing area for the driver. Therefore, keeping your wiper blades working and in top shape is important. Hardening of the blade's rubber, however, can reduce their effectiveness. This hardening occurs naturally over time as the blades are exposed to sun and other elements. If the rubber on your wiper blades has hardened, a few things will help restore their usefulness.
Clean the entire windshield with vinegar followed by a water-and-soap wash to remove grease and any wax that has built up over time.
Avoid getting the petroleum jelly on the windshield. If the jelly gets on the windshield, clean it off with a cloth dampened with vinegar, followed by a vigorous wiping with a cloth dampened with plain water.