I have found (through advice of wonderful people on the FML) that if my
ferrets poop in an unwanted place (given that they already have enough
wanted places to go) I put vinegar where they went.  It hasn't let me
down yet.  I've also put BenGay down on places I don't want them going,
that worked about 75% of the time.its like, you put anything strong
smelling down on the places you don't want them going and make the litter
areas as inviting as you can!
 
ALso, try putting a little of their poop or pee in the place you want
them to go and make the unwanted places smell NOTHING like a place they'd
want to go.
 
But what I've found work best is putting Ferretone on the [well-cleaned]
place you don't want them going.  My ferrets would never poop anywhere
near their favorite treat!
 
Hope I helped, as these pieces of advice have helped me from the FML in
the past!
 
Jen in PA
[Posted in FML issue 4006]