Industrial salt is rock salt, while the bulk of the domestic salt is evaporated sea salt. Rock salt is mined from natural deposits of salt. Often, water is pumped into specially drilled wells to dissolve the rock-salt deposits. The resulting salt is a white color. Some are quite large in size while others are flour like.
Some grains are round in shape while others are flat.
Some salts have a tendency to melt very quickly when coming in contact with liquid moisture, while other salt will hold up extremely well in liquid moisture. The proper salt used can neither be flour like nor very large pieces. The dry salt also should not be of a type that will disintegrate quickly or too slowly when coming in contact with the moist meat or fowl. Iodized salt should not be used at all on Passover. Needless to say any animal or fowl not ritually slaughtered, even after a salting procedure will remain in a non-kosher status.