Have you tried a reverse variant of A, where the inner bag contains solid cacl2 (and, to make breaking it easier, some air or some mechanical breaking aid)? If it works it might be safer than A: you will never get solid cacl2 leaking out.
@8petros I would appreciate if you elaborated on the cost/failure point increase (either I don't see something obvious -- it seems to me that everything should be ~comparable -- or I failed to get the difference across).
Unrelatedly, I noticed:
> The solution that remains after the reaction is completely harmless and can be reused as a food additive
or antifreeze liquid.
~1/4 of that liquid is calcium. Daily recommended intake of calcium is on the order of magnitude of 1g. Random sites on the internet claim that taking more than ~3g per day is a bad idea and NHS claims that it can cause diarrhea (https://www.nhs.uk/conditions/vitamins-and-minerals/calcium/). It might be a bad idea to drink that.