In the Dominican Republic, there are at least three different trees the locals call cajuil. The true cashew nut (Anacardium occidentale) is their cajuil dulce; more commonly, the mountain-apple (Syzyguim malaccense) is called a cajuil; and I have come across a few who use the name cajuil español for the ackee (Blighia sapinda), although that is not its usual local name. What these three have in common is the similar appearance of the fruits; usually, Dominican home gardeners use the "cashew apple," not the nut. The reason is that the nut contains a poison ivy compound which must be removed by processing before it is edible.
I have looked up cashew nut processing, and found a Peace Corps training video at the small-factory scale, intended for Africa. But even at that scale, there appeared to be certain specialized equipment that would be cost prohibitive at the scale of a single homestead. Does anyone know of a practical way for an individual homesteader, with only a few cashew trees, to make the nuts edible?
As a kid I grew up 'processing' and eating the nut.
If all you have is 100lbs of fruit from 15 or so plants, it is easy.
Make a rocket stove Place a sheet of metal on top
Place the 'nuts' 1 layer deep on it.
Roast them until they 'explode' releasing the 'oil in then, which catches on fire, then they are safe to eat.
I probably never ate or processed more than a pound at a time. Not too sure what would have happened if I ate lot of it daily.