The idea is to save on interest by keeping your revolving credit balance as low as possible.
Interest is calculated daily, so try to keep as much money in the account as you can to keep the interest charges as low as possible.
One way of doing this is to use your credit card for your day-to-day spending. This way, instead of money coming out of your revolving home loan account daily, it sits in your account longer, coming out in one go when you pay your credit card.
If you’re going to do this, then set up a direct debit from your revolving credit account to pay off your credit card each month. If you pay your credit card bill in full before the due date each month, you won’t pay any interest on purchases.