sv_cheats "1" use "weapon_crowbar" ent_remove "weapon_crowbar"
This script is very simple, because it disarms you, so other players see you walking without any weapon. If you switch to another weapon you will not be able to disarm again. Also useful for filming, with cameras. This script is not itended to be used in-game as exec Script.cfg, just to show you the commands you need for. However, you can also compile it in .cfg file. Sv_cheats is required. You will enjoy it more if you use my realistic firstperson script, for Counter-Strike source, that also works for GMOD!! Enjoy!