Pargyle
I have grown from 2 to 4 TBH (full size) plus 4 TBH nucs in three years and only carried out autumn thymol treatment - Hivemaker's recipe plus added molten wax and used strings soaked in the mix hanging in the brood nest .
(By their design, placing thymol mix above the bars as you would in a national is impossible).
No oxalic, no brood culling, one thymol treatment for 4-6 weeks August/Sept .
I have never treated any swarms - the mite drops are negligible. BUT I shake all my swarms into empty TBHs to force them to draw their own comb before any eggs are laid so there is a natural brood break which will kill off most mites. (You can do the same by using undrawn comb or just starter strips in a conventional hive).
I have bottom boards - with an air gap - all year round under the OMF so I can monitor mite drops when and if I want at any time.
During treatment (from my records)
Mite drops 2010 (2 hives)- hundreds.
Mite drops 2011 (3 hives) - maximum about 80
Mite drops 2012 (4 hives plus 4 nucs) - tens per hive.
2012 was strange due to weather - brood breaks plus 2 queens lost so I am not growing excited ...
Our local Association has found specific hives have much higher mite drops year after year.. and have requeened in 2012 them in an attempt to reduce prevalence (Discussed in Sat pub meet). They use oxalic and thymol.
So my answer is:
brood break for swarms.. (feed like crazy to help them make wax)
one thmyol treat.
Requeen for persistent bad hives.
Of course if I was a TBH zealot... but I'm not
Icing sugar etc I leave for cake makers.