I think you should be able to disable the whole chat so you're only able to type commands, but not able to type in chat, nor see other people's chat messages.

This would not only disable the chat at the bottom, but also not make the chat messages appear over the mice saying it in-game.

This could be used to prevent young children from seeing inappropriate things (the filter option doesn't block everything), and could just be used to have a more relaxing time playing the game without bothering or worrying about people saying inappropriate or rude things, which is pretty much half of the Transformice community, anyway.

Hi, A couple of similar suggestions already exist.

[Chat] Option To Block All Chat
[Other] "Child friendly" Mode for youngers

Please check the Suggestion List before making a thread: http://atelier801.com/topic?f=6&t=773448