Step 1: Safe ingredient you have on hand!
I have also read about using borax. But the down side to borax is it can hold moisture. So using on your carpets can be a risk if you don't get all of the powdered vacuumed up, it can lead to problems later.
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.