I used a spray drill many moons ago until I lent it to a locum while I was on Mat Leave. When I got it back it looked like it had been run over by a car............literally. Locum long gone; agency not interested
I tended to use it on patients with mental health problems or learning disabilities. The spray kept the drill head cool, so for those really gryphotic nails combined with patients who ere unable to let you know if things were getting a bit warm it was great. Extremely messy though, the slurry would take some cleaning off afterwards. I think they have a place, but not sure if I would go back to one permanently.