Yesterday afternoon we made up some Blue Shop Towel treatments using 20kg of Crisco and about 20kg of menthol crystals. Here are some pictures of the process. (See also recipe)
We cut the towels in three instead of two, since I hear that when cut in two, the treatment may be too strong and kill brood. I figure that having the towel smaller and a bit farther forward will help reduce this risk. I have also heard that it is almost 100% effective with half sheets and so I think I can reduce the power a bit.
After soaking, the towels are drained and placed in gallon ZipLoc bags to keep the menthol from evaporating.
In the third picture is a remote reading thermometer that can read temperatures of objects (and people) from several feet away. We bought it to diagnose engine problems, but anticipate it may be good for determining brood conditions in a hive and other interesting details we have not imagined yet...
The fourth picture shows the towel on the hive. The procedure calls for a second towel to be added in ten to fourteen days
Here is a list of BEE-L references on the topic.