I'm reserving final judgment, but I think it may be worth the dust. I regrouted the fireplace - it went from coral-pink to grey. As careful as I was to not get the grout on the stone, there were inevitable slops. Grout doesn`t wipe terrifically well off of rough stone. A wire brush and elbow grease were helpful, but not nearly as helpful as a nineteen year old with a few hours to kill and a grinder with a wire brush attachment. If you check the hearth you'll see that the black slate is covered in a nice fine coating of dust. It's everywhere. Fun.
Here is the 'before' shot, taken during our prepurchase inspection. Two years ago. Unreal. One day, when people ask what I'm doing for the weekend, I will be able to say something other than 'house stuff'.
And....after. Keelan wore the brush down to nubbins, but not only did it clean the grout off the stone, it also cleaned off years of soot and grime. Now we just have to decide whether we will seal the stone with enhancer. If you look on the right hand side, about half-way down you`ll see six or seven stones that Norm put enhancer on as a test. It definitely brings the colour out, but I sort of like the pale grey too. No need to decide right away - it will keep until after the living room is painted. But first, some dusting. And then we can go pick up a slab of granite we are having cut to fit on top of the hearth.