I believe the studies showed that even the crappy (my word) salt worked to release the toxins from the kidneys.
However, (and I apologize for not printing it before) - I advocate the ancient seabed Seasalt , (I use Redmond's RealSalt) because it is NOT demineralized, NOT bleached, and has NOT been processed.
I have to "tap" my salt shaker prior to salting my food, because it does not have the chemicals added to keep it from sticking when moist.
However, I have no problem in scooping out the 1/4 tsp's worth for each of my quarts of water!