It works AMAZING on most coats. My only complaint is how often you need to sharpen them and how quickly you go through them if you sharpen them as often as necessary. They're fairly easy to shapen, you just rub them against a solid object and it breaks down into crumbles and gets sharper (and smells bad, haha) and you can continue grooming. It just gets dull pretty quickly, but it works really well. I end up putting in a pretty fair amount of pressure and I get great results. Certainly a lot better than shedding blades I've used in the past.
I must add though, that I have come across one horse this didn't work well for. But it was only the one horse. I'm not sure why it didn't work, but I've never had any problems since then.
Yes, you can! Just have a look round your saddlery. I think they're called pumice stones and don't smell them, they smell really bad. There great when I want to clean up there coats a bit after winter. They're heaps easy to use, and I find that they get out a lot more hair than shedding blades do.