How Can I Make the Physgun's Laser Disappear or Not Show Up in a Recording?

I know it’s possible to do this, as it was done in Half Life 2 - Full Life Consequences (or at least in the 3rd one). I saw a video showing the making of hl2 flq 3, and it showed several people with physguns manipulating the limbs of a combine to make him drink from a mug, but the physguns were not in the actual movie.
How can I do this?

If I remember correctly, there should be an option in the spawn menu somewhere near the top right in one of the tabs that allows you to turn the physgun’s laser on or off.

In the top right hand of the spawn menu (Q-Menu) there is a option to disable it under post prosessing.