Sorry for the confusion. That parser can only apply to system messages and not regular user messages. This is noted in the parameters description and is entirely my mistake recommending it as a solution. Applying it to regular user messages would allow them to do things like insert Joomla modules and utilize other CB content plugins like CB Content Bot to substitute in other users data.

A bad words filter is planned for CB Activity 6.0.0 though. However it is possible to add a bad words filter, but will require CB Auto Actions to do it. I've confirmed the below will work.

Global
Triggers: activity_onParse
Type: Code
User: Self
Access: Everybody
Action
Method: PHP
Code:Parameters
References: Variable 1

You can actually use the above to manipulate the resulting message however you like with whatever custom parsing behavior you want. Note the REGEXP was adjusted to account for the final parser result which is a link since you've links enabled.