I've got no idea how MOX works XD.I only know that it's better if it's hot, I would have to look up how to make it, and building something that can perfectly hold the temperature is probably quite hard. anyway, you can get 18M EU/cycle, which is like, 20k seconds? that would be half an hour. and you can do it indefinitely.
I use this with dual MOX cells for 700 EU/t, total 140 MEU per 10000s cycle. 8 cells takes 110 mB of UUmatter, meaning a net gain of 30 MEU or 30 UUmatter depending on your preference. Do bear in mind if you want to use it with regular Uranium cells, it is a Mk II-E and will blow up just before 20000s. To avoid this, either give it some mid-cycle cooldown time or uprate one more of the heat vents to advanced.