Recoil in CS 1.6 is server-side. No legal CFG can remove recoil.
Here's a sample CFG file with some popular aim settings: cs 16 cfg aim best
: Matches your FPS to ensure the server sees your shots exactly when you take them. ex_interp 0.01 Recoil in CS 1
To use a custom aim config, you must place it in your game's directory: cs 16 cfg aim best