Q RE Recent Blog Article on Mortgage Paydown

[Don Ireland]

In one of the most recent blog articles (I just received an email yesterday pointing me to it), the author (@Dave Van Horn) discussed using a HELOC as a sweep account.

It's method #3 in the following link.

https://www.biggerpockets.com/renewsblog/eliminate...

This sounds to me like using a HELOC to make payments on the primary mortgage. But a HELOC would typically have a higher interest rate than that of thr primary mortgage.

So how would this be a benefit?  What am I missing?

TIA!