This is the only reliable method. The Cambalache community operates primarily via Discord. Server owners post the daily or weekly password in specific channels.
The password for the campaign in Left 4 Dead 2 is Tango . Password Details & Usage
: The special weapons (e.g., skateboard, guitar, tramontina) are controlled via the mission.txt file; if they aren't appearing, ensure the manifest is correctly recognizing them.
: The common infected feature localized touches, including textures of soccer jerseys worn by locals (such as River Plate and Lionel Messi kits).