Using Line of Credit to reduce Debit

We are going to open a line-of-credit account at CIBC next week. Our plan is to pay down our mortgage by borrowing from it. We have a fixed mortgage at TD, and the rate is 4.852%. It will be another 4 years until the term is due. The rate of the line-of-credit account is premium plus one point, currently at 3.5%. By borrowing up to 15% of the original amount of our mortgage and double the scheduled payment amount, we can save more than one point on the interest rate. In a long run, this could turned out to be lot of money.

But this is still not the whole story. We can save more than that and may pay off the mortgage in half time. The trick is: put all our cash into the line-of-credit account, including our pay checks. Since we will not spend all the pay in the same day, so the money will save some interest for us. (The interest is calculated daily)

Now I just regret we did not hear this great idea few years ago.