Hi, I have done it some time ago as an experiment, but using only CPU to mine DRK with their free 1 year offer (I had several instances running in parallel then). I have even made a small tutorial on it here: https://bitcointalk.org/index.php?topic=762292 (sorry that it's in Portuguese language).

I was able to mine a very small amount of DRK with this CPU experiment (obviously not viable if I had to pay for the service), but my idea was more to learn how it worked.