Have you ever visited a salt evaporation pond?
I have been to a number of these locations, in France, Spain and the San Francisco Bay area in the USA, and can state that they may produce an edible commodity, but I would not consider it a first choice for wound care without further processing such as filtration and sterilization.
Claims that this evaporation process is more natural that imply it is safer or better than mining or drying salt in concrete basins are questionable. Such claims should be well documented for a product intended to be introduced to an open wound.
How much dirt, dead plant and animal matter and excrement do we really need in our salt?
Historically, many difficult to substantiate claims have been made about possible wound care benefits of sea salt. There are a large number of studies on the subject, including balanced reviews comparing sterile saline to tap water.
For wound care, some alginate dressings among a limited selection of other products incorporate sea salt. These and other unrefined sea salt require further study and evidence for use as an OTC wound care product.