Ben,
 
Each ferret has their own little quirks, and after a while you realize it's
much less frustrating to change the things accessible to your ferret rather
than trying to change the habits of such a determined little beast!  One of
my ferrets chews the toes of my good leather shoes (ONLY the toes, and ONLY
my good shoes!), and she is obsessed with getting her teeth into my hair
brush and the rubber baster bulb.  Nothing else.  So I just have to keep
these items out of her reach.
 
They make J-feeders out of metal, which might work for you.  I don't know
what you could do about the litter pan - maybe try to find one made of a
different type of plastic?
 
Funny story related to the above: I was once sitting in a job interview,
trying to make a good impression, of course, until I happened to look down
and was horrified see teeth marks all over the toes of my freshly-polished
shoes!  I discretely folded my legs under my chair and hoped no one had
noticed.  Didn't land that job, so I'll never know!
 
Nancy and critters
[Posted in FML issue 3447]