Has anyone used this or have comments?

The ‘Magic’ Formula is:
170g beeswax
450g coconut oil (or any vegetable cooking oil)
15g essential oil (we have tried eucalyptus, nutmeg, peppermint and spearmint)
1. Break the beeswax into small pieces.
2. Melt in a double boiler (a large pot with water containing a small pot with the wax) with the coconut oil.
3. Stir until the wax melts completely and allow to cool to 42-45°C. If a thermometer is not available, cool until the mixture just starts to harden at the surface, but is still quite fluid.
4. At this point stir the essential oil into the mixture until thoroughly blended.
The above mixture should be sufficient for 50 hives if applied as follows:
1. Cut strips from any of the following: bamboo, Bristol board, cardboard, plastic containers, plywood, or tins. The strips should between two and five cm wide by 20 cm long.
2. On one side of the strip spread one or two teaspoons of the miticide mixture, distributing it evenly.
3. Leave a 1 cm section at each end of the strip clean to avoid getting it on yourself.
4. Push the strip deep into the entrance of the hive undergoing treatment, preferably before 0900 hours on a hot, sunny day. If Varroa is present, the first effects of the treatment (dead or terminally ill mites on the bottom board) can be seen within 2-4 hours. Presumably the hotter and drier the weather, the faster the effects.
5. After 24 hours (longer for lower temperatures), the treatment is over and a number of dead Varroa can be seen under the brood chamber. Also, and possibly for the first time, white males can be observed dead on the bottom board or groggily walking about in a totally uncharacteristic behaviour (normally his whole life takes place within an invaded brood cell).