I'll agree that sometimes swearing is necessary in a fanfic, but
rather than
spelling out each expletive I prefer leaving the actual word to the
imagination
of the reader.

 ex.  Ranma cursed as he dodged the multitude of weapons Mousse was
throwing at him.

By not putting the swearing into actual dialogue, your characters can
swear a blue streak
and still remain unoffensive to your readers.  That way also leaves
you the option
of having the character swear in dialogue and a certain amount of
shock factor can be
expected from your readers.

Well, that's my two bits worth.