For example two options come to mind:
Salt: using plain table salt to clean your teeth is an oldfashioned idea for those who are trying to cleanse their teeth and mouth with a simple and chemical free option. Just dip your clean tooth brush into some water and then dip into a small mound of table salt and brush as usual. Then, to make a simple mouth wash, you can add hot water with 1 teaspoon of table salt and stir until the salt dissolves and the salt solution cools enough to the point that you can use this as a great mouth wash. Swish the salt water between all your teeth and around your whole mouth. Salt water also helps in cleansing any small bumps or lumps you may have on your gums, tongue or lips. Some health practitioners advise using salt water rinses when you are battling a sore throat. ( this should not replace obtaining proper medical care from a licensed medical practitioner.)
Baking Soda-- This is an old but good one too. Just wet your tooth brush and touch the bristles of the tooth brush directly into a small mound of Baking soda, then proceed to use it to clean your teeth the same way you normally would brush your teeth. Sure, it doesn't taste great, but the gentle grittiness of
baking soda is a great teeth scrubber and will bring about a beautiful shine. Just be sure to rinse your mouth with clean water when you are done brushing to rinse away the taste and any residue.
So, the two above options you can use when you want to simplify your consumerist lifestyle, or when you want to get back to living without the use of harsh chemicals. Some people may use these options when they are trying to save money. Both table salt and baking soda are both cheaper options than buying regular priced tooth pastes. Both Baking Soda as well as table salt are usually available at most discount and dollar stores. Other people use these options just when they find that they have forgotten to pack toothpaste when they go camping or travelling.
Take good care of your teeth, so they can last a lifetime :)