Old stone mortar and pestle cleaning My roommate has an old mortar made from stone that had been outdoors for quite some time. She rinsed it thoroughly,put it in a big pot, and boiled it to kill any bacteria that could be crawling in there. 

The mortar has great sentimental value for her, and I'm unsure about what products use for cleaning, if at all, since the stone might absorb the chemicals and render it unusable. 

This related question seems to indicate that soap is not to be used with porous materials, such as stone. 
Why are stone ware and dutch oven items exempt from bacteria?

Before using it for food preparation, is there anything else we should do to avoid health issues? Can we use it already after boiling it?
What type of stone, lava, marble, granite? Bleach makes for a nice general purpose disinfectant, as it degrades on its own over time. Let the thing soak in bleach (1 part bleach 9 part water) for a few days then boil again, and you should be good to go; once you find a pestle that fits.