Knights only have the power to mute grey users.

So if you're a grey user that gets muted from a model's room, you have to wait 24 hours to be able to chat again to the model’s room. 

However, if you become a Green or Gold user, you cannot ever be muted by any of the Knights. Otherwise, if you stay grey, you'll always have the potential of getting muted for 24 hours from a model's room.