I guess you mean the ssh filter which can be found
here?
Personally I haven't installed this or any other ssh brute force attack blocker (although I am charmed by the concept of many of them).
Currently I think it suffices to disallow username / password logins and stick to ssh key pairs. However if frequent ssh attacks put too much strain on your bandwidth, I can imagine that you want to look for something that takes care of this at the firewall level.
If the latter is not the case I would really suggest to start using ssh key pairs. No valid key combination --> no login allowed whatsoever...