It looks like it combines a couple things you COULD do on your own and charges a big fee to do it, or in some cases a big fee for the special software that will help you do it. The basic idea isn't all that bad, but more risk than I care for:
Open a HELOC account that will allow checks to be written against it and plan to use this for most of your day-to-day expenses
Pay down your mortgage very aggressively. Put almost your whole paycheck and any savings you might otherwise keep into it. Remember you have the HELOC you can draw for living expenses.
In advanced versions, juggle the balance of the HELOC if it has a variable rate, or in some cases use their "secret sauce" computer program to predict when to pay more on the mortgage or more on the HELOC.
In theory, the time that monthly expense cash would have spent in your checking account it is now already applied to pay down your mortgage, so you pay off sooner. Plus you are super aggressive about paying it down, so it pays off sooner.
Hope like crazy you haven't miscalculated or you HELOC gets frozen. You have no free cash and are counting on the HELOC for all your liquidity.
If you want to be this aggressive (too much for me) then I don't see any reason to fork out thousands to do it. I think that some versions of the plan also provide the HELOC account, which is supposed to be protection against a freeze, but I'd want to really really understand the loan agreement and consider contingencies such as job loss or unexpected expense. All the versions I've been approached to join were scams of one sort or another. YMMV.