Hi Mark and all,
I have been using the method of FGMO fogging described by Dr. Rodriguez.
Basically, you fog every other week for about 5 seconds per hive. I'll
admit I've not been doing the cords he describes at that frequency- I've
been refreshing them at only once a month.
A much more detailed account on this fogger business can be found at
www.beesource.com . In their "digital dialog" section you will find a
discussion group about FGMO. An hour spent there should answer your question
much better then I can.
Bee happy,
Don