Evidence? What evidence? What's the chemical being used then? Surely you can identify it if there's "evidence" that this is anything more than this little thing I like to call contrails. Please, educate yourself on more than crackpot websites. You've probably also been deluded into believing that man never landed on the moon.
Can you imagine the size of production, transportation and storage for that much chemical? Many times I have looked out of plane windows to see another passing aircraft and the contrail behind it.