We have used Mite Away Quick Strips on our own hives for several years with great success. Formic Pro is the newest formulation from NOD Apiary Products. It is an improvement over MAQS because it has a two-year shelf life stored at room temperature. (It's best kept in a cellar, out of direct sunlight.)
Formic acid (which smells like ants ) is are one of two soft treatments we recommend for Varroa mites.
Application is simple: one application between brood chambers, and it can be done with honey supers on. Daytime temperatures should be between 50 and 92 degrees Fahrenheit and the colony should be at least six brood frames strong.
Treatment is two strips per full-sized hive. 2 pack (4 strips) treats two hives, 10 pack (20 strips) treats ten hives.