You shouldn't brush with toothpaste which contains glicerine and leaves a film on your teeth which prevents the calcium in your saliva from remineralizing your teeth.
Brush your teeth with soap once and you will be amazed at how much cleaner your teeth are. Or use toothsoap which you can buy at http://www.toothsoap.com.
One bottle last about five months so it's cheaper than toothpaste. Plus, if you get on their email list, they will let you know when they have two for one sales.