You find it hard at the start of a shoot to get a model to hold a piece of white paper, focus on it, and push 2 buttons???
You go to the menu, find "pre-set white balance" select "set" and shoot one time.
You then select that setting as your white balance for the the shoot...how hard is that?
Unless you are having horrible color temp fluctuations with power changes to the lights, you shouldn't have to re-set the white balance for the remainder of the shoot.
Once you have saved a white balance pre-set, you can recall it later (the D1x has 3 presets you can save) in additon to flash, shade, sun etc.