If your couch is stuffed with foam rubber, that is the big attraction.
Same thing with rugs.  The pads are usually rubber.
 
I don't know which comes first in the lexicon of the ferret, rubber or
ferrettone.
 
I have tried the Ferret Store's new extremely bitter stuff, and mine
ignored it.  All I can suggest is Vicks.  They hate the smell of menthol.
You would have to find some way of putting it at the couch where she is
scratching, without damaging the couch.  Other than that, do what I did.
Put a heavy piece of 3/4" plywood on top of the couch cushions.  Take it
off only when you have to use it for seating.
 
Cheryl Nordgulen
[Posted in FML issue 3341]