This idea should be chalked up to "Old Wives Tales", er, I mean,
Folklore!  Apologies to old wives everywhere.
 
The amount of eucalyptus in a cough drop, even a Hall's cough drop is
insufficient to control mites.  There are many anecdotal testimonies
contrary to my assertion here, however this question has been asked
and answered in this forum before, where the final resolution was that
the amount of eucalyptus in cough drops is insufficient to control mites.
When posed to mite researchers, the consensus was that the amount of
eucalyptus is a cough drop (even MANY cough drops) was insufficient for
effective mite control.
 
The claim that you can control mites via cough drops has been debunked
in many learned circles.  Still there are some, perhaps many, who won't
let this myth die, but trust me folks, you don't want to be betting your
bees that cough drops will control mites.  If it sounds too good to be
true then perhaps it is!
 
Aaron Morris - I think, therefore I bee!
 
To protect against cough drops, get your flu shot today!  I wonder if
flu shots can be used to control mites?