I'll second everything John said really. Bone and antler dust is very harmful to breathe in, so dust masks and lots of ventilation are the way forward if you're using power tools to process them. An abrasive stone produces MUCH less dust, though I'd still go with a dust mask if you're working it indoors. Sandstone seems to work best (I found a useful chunk on a piece of derelict ground), though any rock will work (just not as effectively). Wetting it from time to time will also ease the process, and reduce the dust.
As for stench, it's vile. I've never cracked the bones straight from the butcher, I usually bury mine and let the worms do the work. For big bones like beef shins, I'd say you'd want a good month at least. I dug up some two-weekers last Thursday morning and it was all I could do not to yack! Once you've broken them and got rid of the soft marrow from the centre, the bones can be cleaned and then aired to get rid of any remaining smell. Leaving them outside in that state will also help to weather them and kill any smells.
You could smash them by battening a knife on them, but you will definitely wreck your knife. Get in touch with your inner cave man and smash them with a rock - it's much more satisfying! Or saw off the ball joints from each end, then you've got a nice piece of bone to be woring with.
Best of luck with the project - and don't forget to post pictures along the way!
Rich
