Earlier this year I was introduced by a friend to the Miswak, a herbal toothpaste frequently used in the Middle East and Africa. This product is based on a specific plant called Salvadore persica, which in its natural environment can be used both as a toothpaste and toothbrush. It is a twig which can be splited at one of the ends and made into a thick brush.
I personally used for a couple of months the processed product, the tooth paste I purchased from a local Indian store. Nowadays, even big companies like Colgate are creating their own variant of Miswak, delivered in this part of the world. My experience of using it was uneventful, without any serious issues. It took me a bit of time to get used with the taste, a little too bit medicine like, but otherwise I come along with it very well, and not only my teeth look brighter, but my breath quality improved significantly.
According to local studies, the fluoride-free Miswak toothpastes has astringent, anti-bacterial qualities, reducing tooth decay, fighting plague and gum disease. Apparently, it can work as an efficient antidote to germs and bacteria and bad breath too. There are also opinion according to which it can stimulate your taste bids, but I do not have the required medical background to confirm or deny such an assumption.
Obviously, the various food habits and ingredients making the local cuisine do influence the quality of the tooth-health and therefore, requires specific cleaning products and Miswak is also one of them. However, if you have an overall healthy dentition, using it once in a while it is not detrimental to your health.