Id like to know the official answer also.
I do, however, remember him mentioning soaking the veggies overnight. I personally do it for at least 4~5 hours before eating. Sometimes it's been soaking fro a couple of days. I keep my carrots and celery etc for my juice in a bucket of dilute H2O2 and filtered tap water.
For soups I chop up the ingredients into little pieces and soak overnight or at least 4~5 hours in the cooking pot, then dump the water and refill before cooking. And I cook with low heat in a glass pot.