I live in France and ir has been in the top 30's so I thought a solar oven was ideal for cleaning the dirty wax and ending up with beautiful clean wax. I made one, I used a strip of aluminium to put the wax on that I found in the local hardware store and left it for a couple of days. The result was not as good as I had hoped,I don't think that it was in the sun for long enough. I gave in and put the old wax on the aluminium strip in the Halogen, water in a dish at the bottom meant that I ended up with a beautiful round disc wax. The temperature was best at 150