THis is from the FAQ at www.westonaprice.org:

Q. When soaking nuts, why is the salt needed?

A. The salt helps activate enzymes that de-activate the enzyme inhibitors. For grains, we soak in an acidic solution to get rid of phytic acid. Nuts do not contain much phytic acid but do contain high levels of enzyme inhibitors. The method imitates the way the native peoples in Central America treated their nuts and seeds--by soaking them in seawater and then dehydrating them.

Q. Should I consume only raw foods so I don’t kill the enzymes?

A. What the enzymes do is help digestion in the upper stomach, where there are no digestive fluids. But most foods are not good sources of enzymes. You need to lacto-ferment the foods to get a lot of enzymes. So the lacto-fermented foods eaten with cooked foods more than compensate for the loss of any enzymes in the food you cooked. Lacto-fermented foods are 'super-raw' foods. Lacto-fermented foods also provide lactic acid and good bacteria, which do survive the digestive process.

And here is a link to a PDF paper on making snacks that goes into detail about soaking nuts overnight. tinyurl.com/ndwa9