I know this has been brought up before, but I have another suggestion
instead of wood pellets for the litter boxes since they are so difficult
to find in Florida and maybe other states as well.  Why not use rabbit
food instead.  I used wood pellets years ago also because they were cheap
but I realized how the large size and the hardness of the pellet would
feel on those tiny soft ferret feet and between the toes.  I personally
would not like walking on them - ouch!  I switched to rabbit food because
it was still inexpensive, only a bit more in cost than wood pellets, but
still a lot cheaper than actual ferret litter.  You can buy 50 lbs. for
less than $10 and it's available everywhere.  The rabbit food pellets are
much smaller and softer than wood pellets and much kinder on those tiny
ferret nibble toes.  Besides it smells good and my ferrets don't eat it.
I've had a couple of them try it, but they lost interest very quickly.
[Posted in FML issue 3566]