Sodium chloride is common or garden salt. You can also get course salt from supermarkets at a lot cheaper than R40/Kilo. I think Calcium chloride is a more effective dessicant than salt, it can also be reconstituted by heating it but I don't know how much it costs. Problem with heating sodium chloride to dry it after use is that you'll end up with a very solid mass rather than crystals so you'll need to grind it somehow to get it back to flakes.