Q: What is the best treatment in your opinion/experience for treating mites?
 
A: This is a tough question to answer.  But since you asked my opinion, here goes!
 
I do not like to treat my hives with chemicals.   Rather I use two other methods sometimes alone and sometimes together.
 
One is drone brood traps.  This is a green frame with about 4000 cells for the bees to build drone brood and for the queen to lay eggs in the drawn drone comb.  It is available from a number of bee supply dealers.  It is inserted into a strong hive and the bees are given an opportunity to draw out the comb on the frame.  Once comb is drawn on the frame, the queen will usually lay unfertilized eggs and the larvae in the cells draws female Varroa mites to reproduce on the developing drone larva.   The frame is removed from the hive before the drones begin to emerge and is frozen to kill the drone brood and the mites feeding on the drone brood.  The frame can then be returned to the hive for the bees to clean up — a good hygienic test is to see if the hive does clean up the frame in a timely manner.  I use this to test the hygienic behavior of my queen stock as well as fight the Varroa mite.
 
Second is brood interruption which is simple.  The queen is removed to a nuc hive to be later recombined to her hive.  In the meantime no eggs means no brood for a period of time.  Something like when a hive swarms naturally.  With no brood present the Varroa mite can not reproduce.  If a queen is removed the hive will set about trying to raise a new queen using the emergency queen replacement instinct.  You can cut down all the newly created queen cells or let one of them emerge.  If the second is choice is selected, you will have to find the new queen and then return the old queen to the hive.  Or you could start a nuc with the newly raised queen and then return the nuc hive with the old queen using the paper introduction method.  That is also very simple:  just take a double layer of newspaper, lay it on top of the old hive and frames, set an empty box to fit the frames removed from the hive, remove the frames from the nuc and place them into the hive above the newspaper.  Place the inner cover and lid on the hive and wait two or three days.  The bees in the bottom hive will eat thru the paper and the bees will recombine as if nothing had happened.  
 
The bees flying from the nuc location you just used to reintroduce the queen will help add bee population to the nuc you made up with the emergency raised queen if set in the same location.  You can evaluate that queen for future use if you find her to be a good queen.
 
Dana Stahlman