HELOC payoff strategy

[Brie Schmidt]

Twice recently people have told me of this new strategy to use a HELOC to pay off your mortgage faster. You essentially take out a HELOC to pay off your first lien, and then use that account to direct deposit your paycheck and make it your primary banking account.

From what they are telling me, it seems you can accomplish the same thing by making extra payments on your loan.  

The difference is your mortgage is fixed for 30 years and the HELOC is variable with an annual fee

This sounds stupid.  What am I missing?