Sure. But that is just an alternate way of accomplishing Rob Carrick's advice, since you then effectively make one more monthly payment per year. Here are three ways to do pay off principal faster (maybe there are more):

- occasional lump payments (what Rob was discussing)
- paying the same amount more frequently (accelerated payments)
- paying a larger amount with the same frequency (a different variant of accelerated)

For sure any of those will have an effect. If that was everyone's point, then fair enough.

Nonetheless there does seem to be confusion on this score. If you commit to spend a certain fraction of your income (equivalently, a certain number of dollars per year) on your mortgage, whether you pay that amount on a weekly, biweekly, twice a month, or monthly basis doesn't really matter much. At that point it is more a matter of what works best given your income cash flow.