You can deactivate a weapon perfectly easy.
Do that but have it as a trigger_multiple and OnStartTouch or OnTouching. And change the tf_weapon_parachute to whatever weapon you want blocked, using
this. If the player hits a regen brush after leaving the weapon remover brush they will get the weapon back. A quick warning though, this may completely disable the weapon for everyone on the server.
I haven't tested this at all. Also I can't think of a reason to temporarily disable a weapon on a map, but whatever.