While wd40 will clean the rubber blade, it's also an oil based solvent. The correct way is to clean the rubber with some IPA (Isopropanol/ spirit locally). But more importantly, get yourself a claymit or claybar and use it to first clean the glass itself. A clean glass and a clean blade will give you the best results.
If you want to even avoid using your wiperblades, get the glass protected with some sealant (aquapel is a great product that easily lasts over 6 months). I however have used water based sealants which last 2-3 months. Even in heavy rain, your windshield glass stays clear as it repeals the water droplets. You literally don't even need to use your wiperblades. The occasional one or two wipes from time to time
