I don't believe that regular salt is a problem, unless someone consumes too much of it. I guess for the general population iodized salt is better than plain salt, even though it has so little iodine, and some claim that only around 10% of the iodine in iodized salt is absorbed. For those who are so iodine deficient though, every bit helps. I use plain salt to rinse my mouth, and iodized salt for consumption. Sea salt is okay for consumption, but unnecessary to use for rinsing your mouth. Plain salt probably works better for that anyway.