@Don Spafford@John KaiYou are 10-12 years too late for this. The value of the strategy is no longer available in the US. What you are doing now is overcomplicating a simple Suze Orman or Dave Ramsey payoff strategy.
Here is how the strategy worked in the good ole days...
-Some banks and credit unions combined a 1st lien 30yr fixed rate loan or ARM with an embedded HELOC. Except the entire loan could be a HELOC. But there was only one loan balance and one monthly payment.
-The idea was that you parked all of your cash at the bank and the bank only accrued interest on the net balance. So in theory your w-2 income was deposited into the account reducing your mortgage principal and over the month you would pay your bills and the balance would rise back up.
-The win for you was the reduced interest paid over the month on a somewhat smaller balance. The win for the bank was additional cheap deposits that they could redirect to more profitable, short-term commercial loans.
-Where we really made our money was gaming the system so to speak.
-Mortgage rates were 6-7% depending on your desired term and index. Other banks and credit unions would offer prime + HELOCs with a two year teaser rate of 1-2%. You would move your 7% first lien money to your 1% HELOC and rake in the cash in the form of reduced borrowing costs. Once the HELOC term ran out you would rinse and repeat.
-If you had lots of properties you could essentially bring your cost of funds down by 50%. Scale it up and you were basically printing money.
-The arbitrage is now gone. You can still work it but your yield is basically zero. Your better strategy is to just pay down your debt. The secret of the good ole days was having the 1st lien double as the HELOC. Those days are over for now.
-The game will come back when mortgage rates go back to 7-8% and the teaser HELOCs return. But I'm guessing we are a ways from that.