Funny you should mention sandblasting, last summer, they had a special offer on at one of the local stores (Aldi I think) - sandblasting kit for an air compressor - really cheap.
I bought it and never used it until a couple of weeks ago - first job was removing some paint on an old metal detector find from the beach, but I fancied trying a sandblasted wooden sign.
I cut the mask from some old fablon (self adhesive vinyl) on the laser (oops - vinyl
) - worked well, so tried on a sheet of picture glass - outstanding ! OK, you wasted the mask each time, but great results and probably took much the same time as rastering. Bit of a mess with the grit - really needs to be done outside. For a large job 'though, it would be better than rastering and multiple overlaid masks could produce large jobs. Results on glass were VERY even. If anyone is that interested, I can post a pic.
Various options on grit (silicon carbide) or sodium bicarbonate for extremely fine stuff (BTW, sandblasted bicarb is great for cleaning up old model aircraft engines