I’ve occasionally heard people ask about needing to clean diamond stones but I’ve never noticed any buildup that couldn’t be cleaned out with an air nozzle or a few licks of the Super Eraser. I don’t put that many hours on my stones, so maybe it’s something I have to look forward to.
Are your stones actually being plugged up with metal filings? Come to think of it, when I was a young buck, my mill files would plug up if I was working soft metals or wide surfaces. I remember one of the old guys telling me to rub chalk on my file to keep the grooves from plugging up. That’s not meant to say that you ought to try rubbing chalk on your stones, but rather that there maybe are other conditions that could cause the problem, and I’m really curious as to what is causing it to happen to you?