I have had some experience with both CaCl solutions and the sodium acetate hand warmer packets. Please note that I am not a salt research scientist, nor any other form of pedigreed professional. Take my comments with a grain of whatever you see fit.
The experience i had with the calcium salt was awesome! I used it in a desiccant waterfall dehumidifier like the LEAF home demonstrated. I cobbled it together using a little feng shui fountain indoors that held maybe 2 gallons total volume. It was plumbed with an overflow like a toilet.
Outdoors, I assembled a solar desalinator out of half of an old sliding glass door (maybe 2 square meters), some spare HDPE pond liner, and some 1" XPS board. The water was drained to waste, and did not kill the flowers it fed with salt poisoning. I fed the indoor fountain with a little solar fountain pump, same thing I run in the 5 gallon waterfarm buckets instead of an air pump. The assembly was not super airtight, and held about 8 gallons of salt water. I filled it with a saturated mixture of pet-safe ice melt and tap water mixed up above the wonky point on the saturation chart. The most active region for this evaporator was in the 120 - 180 degF range, perfect for any functioning solar collector. On a hot day, the brine solution climbed up into the 150's in the collector.
I did this stuff somewhere around this point in this thread:
http://ecorenovator.org/forum/33290-post42.html
I wish I had taken pictures of it. I tried it out in my parents' south-facing sunroom for about a week. When it worked, I moved it to grandma's house to dehumidify her dank basement. It kept her phase-change dehumidifier from running down to about 20% rh until the lawnmower man threw a rock into the sliding door while cutting the back lawn. Rather than rebuilding the rig, I pretty much repurposed it into the garbage.
The acetate hand warmer bags I had worked pretty well for a few years, maybe 4 or 5. I had three of them, and none of them popped or leaked. I used them on hunting trips and such. One day, they turned up missing, and I didn't replace them. A friend who worked at a warehouse gave me a big box of hot hands packages that fell off a truck or something. The hot hands packs stay warmer for longer in your pocket, but cannot be recharged. I probably put the acetate bags through 200 cycles or more, plus what other people used them also. They worked as good the last time as when they were new.