I used to use rainx when it first came out in the 70's. Then I heard how with some windshields it was etching the glass. I was told if you used it frequently this was a problem??? Stopped using it. As far as spraying silicone on the blades, I know what it does for rubber but not sure I would want that spread all over my glass. At night it could be a problem. Rubber does dry up and become hard and noisy. I new set of blades will eliminate this.