by M
I find that the arbor mounted diamond wheels that fit into a drill or a rotary tool
(http://www.harborfreight.com/4-piece-large-diamond-grinding-wheel-set-32397.html)
work well with the wheel and tungsten submerged in a vat of water. In this manner you can sharpen without the grey tungsten dust ending up in your lungs or on your floor. The stuff really adds up fast. I already have a cake of fine dust at the bottom of a small clear plastic container full of water I was sharpening in and I am really glad I did not just inhale half of that grinding it the way everyone else does.