David,
You're right, Dean Johnson had a little featurette about fixing squeaks this way. Find the squeaky spots and dump some baby powder/talcum powder around the board and use a rubber mallet to tap the board--this will help vibrate the powder down in-between the boards to help quiet the squeak. The tapping can also sometimes help snug-up loose flooring (although this is also typically a temporary fix).
If you get desperate and you're trying the least invasive repair, you could use some finish nails and a nail set. Face-nail the squeaky board(s), recess the nail head with the nail set, and fill the small nail hole with a wood-fill pencil. You just rub the filler into the hole and buff with a cloth--works great and isn't noticeable.