Andrew, in the future, you might want to consider the terra-patties that
are available inexpensively from Mann Lake. They are like hamberger patties
that you just toss on top of the brood chamber, (actually in my experience,
throw them in anywhere). I had one hive which had foul brood so bad that it
stunk from outside the hive, and probably a third of the brood was putrid.
I treated with these patties at the same time as with Checkmite, and that
was a mistake, because after the 8 weeks as I took out the Checkmite
strips, I couldn't remember which hive was infected, and all the hives were
strong and healthy.

Also, even though I doubt that people in my area of the Central Coast of
California have big problems with Tracheal Mites, the grease in the patties
makes me feel that I've done something responsible :-)

Regards
Tim