"I've heard of people brushing their teeth with salt. Is this healthy or not?"
We are not surprised that people are now doing this, or that it is being hyped. It is proof that a little bit of knowledge is a dangerous thing. Sea salt is a great source of trace minerals, so some people figured that it could help to remineralize the teeth. The problem is that we need the right minerals, in the right amounts, and in the right ratios with one another. While sea salt really is good for the overall health as part of a nutritious diet; sea salt's mineral composition in no way resembles that of healthy bone material, and it is therefore unlikely to be truly beneficial to the teeth if it is used as a cleaning agent. We believe that it has a poor help-to-harm ratio, since its excessive sodium is combined with abrasive materials that are likely to destroy tooth enamel with long-term use. We even discourage the use of baking soda, except for occasional use. This is a topic wherein we have done extensive research. You may wish to check our store for our dental cleanser product. The best primary source for dental research is the late Dr. Weston Price, who inspired our formulation. We apologize if our mention of the product seems like gratuitous marketing, but we sincerely believe that it is the best of the best. This is because its ingredients are more-or-less natural to a degree that no other safe and effective product is, and because it is based upon the trinity of minerals that are needed for tooth remineralization, which are calcium, phosphorus, and magnesium. The calcium and phosphorus in our product has maximum bioavailability, because they are derived from concentrated milk.