So I have a fetish for clean forts, I can't stand all the spare stone lying around. So at first I was using k to mark each stone, and that was unbearable.
Then I read someone's tip that you can use d>b>d to mass designate dumping, and that was a lot better.
I recently figured out an even better way, which I assume many others know, but wanted to share just in case.
My fort is located above large chalk layers, so that's the only stone I use for anything, construction, furniture, mechanisms, etc. So basically, when my miners have dug out an area there's lots of chalk, felsite, orthoclase etc strewn all over the place and even using the designate can take forever.
So instead I just go into stocks (via z menu), go to stone, and dump entire categories. It's great! My haulers take all the useless garbage to the the dump where I can atomize it, leaving every piece of chalk untouched. Right now my stone menu has about 1600 chalk, some metal ores, and 3 pieces of granite I left in my magma tunnel to build walls so I don't have to haul stone out there when I'm ready to breach.
When I want to quantum stockpile the extra chalk, I delete my atom-dump, designate a new dump near my mason's shop, and I can use the mass designate tool to dump an entire layer. Since it's clear of other stone already, I get all the chalk in one fell swoop. They dump it, then I reclaim it and voila, quantum stockpile and a nice clean fort.
Hope this helps someone