Here's a suggestion.  I've never had to do it, so it's only a theory in
thought.  How about putting the soak solution in a bathtub of water that is
about 1 inch deep.  Set your ferret in it (all four feet though) and then
offer Ferretone to keep them from trying to drink the water.  She will be
in it, can't get out, and preoccupied.
 
Hope this helps.  :-)
 
April and the LOVES Ferrets
Luna
Orion
Venus
Eros
Sola
[Posted in FML issue 2997]