Done with just a little care to make sure you're reading the tape measure accurately, that method is a very tried and true way to set your toe-in. That's even how most 4x4 shops set the toe-in after installing a lift. I've used that method for 7-8 years and my tires have always worn perfectly evenly, go for it. Having someone help by holding one end of the tape measure will help a lot. Just make sure you're measuring at the same location on the tires and that the tape measure is reasonably level. Straightening the steering wheel using that webpage's instructions couldn't be easier.