I know some people across the pond that use greyhounds for hogs... Pakistan and Afghanistan. Really pretty incredible dogs... They may have a bull breed somewhere in there on some of the dogs, but some use straight greyhounds and seem to get the job done. None the less, a really interesting animal. Not exactly a fan of how they do it over there, but interesting nonetheless. Good find on that literature there Ruben!
I have seen in pakistan and other parts of the middle east where they use Saluki's. They are incredible if you ask me. They look very similar to a greyhound just have about 10x the stamina. There are tons of video's on youtube of them hunting antelopes and gazelle with them. Amazing speed and endurance they have.
That region of the world is were the Saluki stems from. Some strains such as the desert dogs of the bedowins do not have the feathering. I haven't seen the video so i ain't gonna say they aren't greys but if I was a betting man, I would bet they are no more than 1/2 grey if indeed they do have grey in them.