Final I found the way to disable the most annoying L4D2 (it should work for CS:GO too!) post process effects WITHOUT CHEATS! It disables:
boomer vomit refraction,
foggy look on rainy maps (no more fog on The Passing campain!)
pills and adrenaline effects (not all for adrenaline, it's still visible that You used it!),
It is simple addon that works online (any server that have addons enabled!), it's 100% safe, it won't make You VAC banned, it's not a cheat, it makes the game a lot prettier!
So ... what You waiting for? Download and enjoy L4D2 without shitty filters that ruins the game graphics!
A bit late update, sorry for that. I have added dummy .raw files, so it definitely removes the color correction now.