I personally don't swear. I feel it is pointless and offends many.
Anyways, to answer your question: I wouldn't recommend a profanity filter. Why? It can block you from saying normal words. If you block "hell" you won't be able to say "Hello."
Consider adding "no swearing" as a rule. You can say "family friendly" when advertising your server and you will get more players. Trust me, I know from experience.
Try finding some people you can trust and recruit some Moderators.
