Ferrets love couches, and a lot of people have gone to getting the futon
couches which I don't care for plus, since I had my oversized couch brought
in, I have changed the only door it would fit in 36" removed and a 30"
installed so thus, to get rid of mine I have to take a chain saw and
realign it just a little, in at least 2 pieces if not more.
 
So, I located 3 area's of the couch they like to get into and slit the
lining (its inside and didn't hurt), they no longer can use it like a
hammock, and the only other NoNo place, I stuffed the area with an old
sheet to where it filled up the area, they can't get in there.
 
BUT what happened to solve the problem AFTER I did all that = I simply
drapped their cages where no light gets in during the day, or at least it
is very dark.  When they are going through the couch, once they have fully
investigated it, it is normally to find a dark place to nap.  With their
own cages being dark, they will go back to their comfy hammocks or whatever
and will lose interest in the couch.
 
But, if I may, please don't scuff them when they come to you.  They won't
really understand it was cause they were in the couch, instead the last
thing that happened was you squeeked for them to come, and when they did,
they got scuffed.  They will connect the latest thing that happened to the
scuffing rather than think "oh 15 minutes ago i crawled in a place I don't
belong, therefore I am being punished for that not for coming to you and
will then connect scuffing to the squeeking.
 
So I would suggest instead of covering your couch, to stuff the area with
the sheet, drape the cages OR provide a dark place to get into.  After
about a week, take the stuffing out and see if the problem is solved.
 
Millie and the testing, how far can we go, where's the limit noble
cleaning crew
 
Easy Off:  the most perfect ferret in the whole wide world
Ammonia:  Do mice come chocolate coated Uncle Bob or do you just use
          ketcup?
Cascade:  Oh look, Dizzy, Grandma is making a hammock just for TWO!!!!!
Ajax:  Opps, that mouse got away, didn't mean that lively, Grandma
Dizzy:  Good, that hammock will do for Ajax, he's up there at 3.8 lbs.
Joy:  I want one with a zipper where I can zip it from the inside
[Posted in FML issue 2523]