I have avoided the standard chemical treatments after they didn't work *and*
I became concerned for my pets (and my) health.  The product that I use
(there are others but this is the one that is convienient for me to buy
here) is FLEAGO.  It is Sodium Tetraborate Decahydrate which is (as I
understand it) is a type of mineral salt that dehydrates the fleas.
 
First you vaccum your carpets (put a cut up flea collar in the bag first)
then you spread the powder on all the carpets and work it into the fibers
with a broom then wait five days to vacum again.  It may take a couple of
weeks to kill all the fleas but after it does it can be effective for up to
a year.
 
The address for this particular product is:  FLEAGO Industries, Inc.
Naples, FLA  33963
 
Good luck!
 
Your friend with ferrets,
 
Paul
[Posted in FML issue 1588]