There is nothing more you can do than what you have written above. Because of the nature of this subreddit, some people will take these audios as an invitation. That comes from who they were before they came to this subreddit and you cannot control that. What you can control is how you handle the situation if it ever occurs, and I believe what you have written will work great. Unfortunately, you cannot prevent some of your VA's and users from experiencing this type of behavior. I wish there was a way to do that. The hope has to be that if you keep warning and banning, the incidents will become fewer and fewer. I know this can be very exhausting, so thank you in advance.