Don't throw out your Pine Fresh litter.  The pelleted litters like Pine
Fresh, Gentle Touch, etc.  are very different from cedar or pine shavings.
The shavings are quite bad, but pelleted litters aren't.
 
By the way, Gentle Touch brand pelleted litter is great.  I like it much
more than I like Pine Fresh and others.  I believe it's aspen based rather
than pine.  It smells better, lasts longer, and has smaller pellets so it's
gentler on tiny ferret paws.  Call 402-371-3311.  Located in Nebraska.
Unfortunately for me, I'm on the east coast, and shipping from Nebraska to
me it outrageous, and there are no distributors near me.  But if you are
able to get Gentle Touch, I highly recommend it.  Oh, and I'm told they even
had a ferret in their tv commercial!
[Posted in FML issue 1977]