This may sound a bit strange, but try biting him back.  Finnegan would not
respond to any of the recommended deterents.  Out of frustration one day as
he bit my feet, I scruffed him & bit him on the neck.  It worked like a charm
& he rarely attacks feet anymore ( except his arch-enemy's ma).  I had read
somewhere that this was how their mother would reprimand them, & I know that
it is how they assert dominace; I decided to give it a try.
 
Good luck,
Elfyr & the Finn. ( who is at this moment attempting to unlock Tiki's cage...
this should be an interesting 10 days. )
[Posted in FML issue 1241]