well my suggestion is simple, adding that you type a reason when you remove everyone from CITBook. why is that? well because when someone removes everyone from his CB he probably has a reason, for example, I have RL problems and I want to play in silence so I'll remove everyone from my CB and add a reason "I want some alone time and will add you later, please don't message me these days". so that's my suggestion and let me know your opinion about this.