I'm not sure if ferrets will use a scratching post but I bought a
handmade (from a shelter) two story ferret box/cubby-hole playhouse.
(clearly I'm not really sure how to describe it).  It's made of wood and
completely covered in wood.  My fuzzies go in there to play and nap, but
they love to go in now and then and dig as much as they can.
 
Not sure if it would stop most fuzzies from digging in other spots, but
it is a good cozy dig site!
 
As far as digging in front of a closed door, until they can reach the
handle I don't think there's much chance that they'll stop digging there!
LOL
 
Risa
[Posted in FML issue 3848]