Domeyhead

I'm always a sucker for sharpening aids that speed things up. The latest I've seen is a little grinder bit from some Chinese outfit called Vyjoy that fits into a Dremel-like hand held tool, with a metal fan and some angles marked on it. It's like using a hand file in a gauge but quicker. Problem is you only get one grinder bit per pitch size so it's not economical for anyone doing a lot of sawing. I already have a little hand held rotary tool but does anyone know if /where its possible to order multiple bits of the desired size and not one of these job lot packs of accessories 95% of which I don't want? Also has anyone used a dremel with grinder bit to sharpen their saws - does it work? Thanks .