A basic check confirms that this is BS. In their own example, the Mortgage loan is 6.5% but the HELOC is 8%. You are paying the mortgage with HELOC money, meaning you are paying down a loan rate of 6.5% with money from a loan rate of 8%. (Paying down cheaper money with more expensive money.) You really want to do the reverse.

By the way, many credit unions as well as brokerages have checking accounts that are interest bearing. Even some banks do to. Yield is not always that great, but you should use 30day, 60day, 90day CDs as well as Money markets etc for any amount over 1month, 2month… etc needs.

They are trying to sell this POS software. The interest saved is really interest saved compared to not paying the mortgage payment that month(which is not advised). One can easily do this with an eXcell spreadsheet. You will actually save more money by prepaying one month (which is what they sort of state the software as costing) than buying this POS.