I'll give this short thrift because this post from "SearchLightCrusade" goes into incredible depth debunking Money Merge Accounts or MMA's.
But the bottom line is that when something sounds to good to be true, well then, it is. I actually dismissed the concept outright when I first heard about it for two reasons. For one is just it made no logical sense. How could you pay off your mortgage in half the time without paying anything extra? Secondly, if it was that good wouldn't EVERYONE already know about it and be doing it? Wouldn't Oprah include it on every "save money" show, and Suze Orman bring it up on every show?
The concept in a nut shell is that you set up either a HELOC (Home Equity Line of Credit) or get a special mortgage where you direct deposit your income into it, thus lessening the interest. You then pay your monthly bills out of that account at the end of their 30-ish day pay cycles. So instead of the bank floating your money for30days and making money off you, you float it and save the money. Finally, there is very expensive software that will read your budgeting and recommend when you pay extra payments.
It all sounds very convincing.... but to to skip to the punch line, the only part of this that really has a major impact are the extra payments, and you can do that on your own by either making a random extra payment, or paying every 4 weeks instead of every month (there are 52 weeks, not 48 in a 12 month year). And per the SearchLightCrusade post one extra payment per year on your mortgage pays it off 8 years earlier.
Paying an extra payment per year is free, and you don't need to shop for special mortgages or get a HELOC. Besides, these funny money schemes were mostly touted when everyone had access to easy money. All mortgages and HELOC's are much harder to get these days, AND usually the Money Merge Account ones are more expensive.
So take a free piece of advice.... if you want to pay off your mortgage early, make one or more extra payments per year. Your first extra payment can be the $3500 some of these slimy outfits want to charge you.