I can not in good conscience consider that treatment regimen to be "treatment-free" for several reasons.  My objections may sound pedantic but I believe that definitions are important.
 
1)  MAQS and thymol may be "natural" pesticides since they are also found (in greater or lesser concentrations) in nature but it is a mis-statement to call them "non-pesticides".  They are introduced chemicals which kill the pest.  By definition, that makes them pesticides.  A non-pesticide treatment would be a mechanical control such as drone brood culling.  None of the chemicals can ever qualify in my opinion, regardless of their source.
 
2)  Single treatment is still treatment.  So is requeening.  Requeening is another example of a non-pesticide treatment but it's still something being done to the colony by the beekeeper.
 
The standard you are arguing for is not "treatment-free" but "persistent-chemical-free".  Being free of persistent chemicals is a laudable goal.  Arguably, that is a better goal than the ill-defined and highly suspect "treatment-free" standard.  But to be fair to ourselves and our customers, we must be precise in describing what we do with our bees and our honey.
 
To your tactical question of when in the year would that strategy be best employed, the answer has been discussed in the archives many times (making it surprisingly hard to find).  The short answer is that it depends, largely based on your local climate and growing season.  In northeast Ohio, we would consider mid-August to be probably too late.  Your new queen would not be settled and laying in enough time to raise a new, mite-free cadre of workers to raise the workers who will care for the workers who will need to survive the winter.  That's not to say I wouldn't try a rescue if I discovered the investation that late but shame on me for waiting that long to check.  In San Francisco, though, mid-August might still work.  Count back at least two and preferably three generations of workers from when the queen typically stops laying.

Mike Rossander

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