Mortar used to process paste containing candlenuts - risk of contaminating raw foods?
Didn't even know they were toxic uncooked, and survived 40+ years of home cooking (both by me and my parents) without any ill effect, I would say 99% of the times ground uncooked. 

That is, however, not an answer, so I will just explain my point of view, and why I won't bother with extraordinary cleansing after grinding candlenuts.


I can't find anything on the toxicity levels, other than "mildly", and never saw any warning on any bag of candlenuts. I did find it on some other "exotic" ingredients, most notably mustard oil.
Not a very strong argument, but: Usually, somewhere between 5 and 10 nuts are used, tops. For a mildly toxic ingredient, this seems quite a low number to make it dangerously toxic. 
It seems unlikely to me that after grinding you end up with 99% of the stuff going in to the dish, and yet somehow, a significant, if not most of the amount of toxins remaining in the mortar.
Recipes sometimes do tell to toast the candlenuts first. None of the ones I know of say it is because of the toxicity. All of the ones I know of, tell to toast them lightly, a few minutes max. Given the size of a candlenut, it seems unlikely to me (but I'm not chemist) that toasting it for around 2-3 minutes will kill the toxins. Come to think of it: None of the books, recipes, or sources otherwise ever even mentioned their toxicity.
Lastly, and completely irrelevant, I may be the lucky one of course: I'm still here breathing.


All in all, I personally group it into the "Tomatoes and potatoes are toxic" category. Both nightshades, but you'll have to eat a ton of them in one sitting before you'll have to start worrying.