Mix the flours and salt in a bowl. Next combine the vinegar and soda in another small bowl, quickly dump it in the flour mixture as it reacts. Then quickly add the water. Whisk well. Let this sit for about 5 minutes, it will thicken.
Meanwhile heat up a frying pan with about 1-2 inches of oil. Mix your chicken pieces in the batter and let them sit in there while the oil heats up.
When the oil is hot, drop your chicken pieces in the oil one at a time. Don’t drain the excess batter off, just hold it over the bowl for a sec until the dripping stops. Cook until golden brown and cooked through.