Using credit card to pay mortgage for less interest?

[Ben Kirchner]

I attended a seminar yesterday.  I didn't know much about the company.  I still don't know a lot, but the company was Renatus (myrenatus.com).  The presenter talked about paying off your mortgage with your credit card to avoid the front loaded interest in a typical mortgage.  Below is an example used to communicate her

$200,000 loan, 30 years, 4.385 interest

With the amortization: $1000 payment per month - Your numbers in year 1 would be:

$8704 going toward interest

$3293 going toward prinicpal

If you paid for the year with a credit card with 21% interest, you would pay $12,000 in principal that year, while paying only $2520 interest toward that credit card.  Essentially saving over $100,000 and paying your house off earlier.

What people of course were asking - Pay your mortgage with a credit card?  Her short answers were cash advances or paypaling money from your credit card.  Unfortunately, questions started to lead the presenter down a different path, and I had to leave the seminar to get to an appointment.  

This is the first I've heard of this concept.  I'm wondering if anyone has experience doing this and can shed some more light on it.  All help is appreciated.