yes, but its still very very hard to get all the workarounds. They can not only make workarounds such as Æuck (not recognised as a normal f), they even make it appear as the normal word, yet the filter will not pick it up. like for the word fuck, you can just write [ b ]f[ /b ]uck (enclosed in B tags), and the filter wont pick it up, yet it will appear as the normal word.
So it really is incredibly hard to stop, or even slow down. People will swear when they want to, this wont stop them at all. All you need is tight rules on your forum about swearing, if you view your forums enough you can issue warnings to the people that swear (and edit their posts), and if they repeat it then you can ban them. (if you take it that seriously that is)
filters never stop anyone, If you want to swear on a board you just do a workaround, you don't generally just decide not to if the filter picks it up as a swear word.
I agree with paul, I don't really want the censoring feature, I have no need for it.