Hello hipchick,
Yes, Redstop does work thankfully, I've just used it as the final solution as my girls were really suffering, one very large coop, and a much smaller one not infected, until the little b.....s decided that they had had enough of constant bombardment and decamped to the smaller coop.
Diatom, constant spraying, cleaning, I also resorted to smearing all perch ends with citronella oil, can't stand the smell, but the conbination seems to have worked.
I also do keep up the advised weekly dose of Redstop.