Yeah, when I downloaded MSI Afterburner it came with Kombustor, a Furmark made tool.

I think people say "don't use Furmark" to mean that you can't use Furmark as a sole basis for stability. I have been Furmark stable for 30 minutes, but have found that during games I might get lockups or crashes I wouldn't normally get, and it has to be attributed to an overclock that isn't truly stable. Sure the games run at a lower temp and don't seem quite as demanding, and they run fine 95% of the time, but every so often they'll have a short hiccup or something I wouldn't get if I turned down the overclock.

I haven't used GPU Tool's artifact scanner, I will have to give it a try. OCCT's GPU stress test has an error check, but it notes that the error check reduces GPU heat because of large data transfers required for the error check comparisons.