I also have a bunch of the old fashioned canning jars with the glass lids. I can still find the rubber gaskets to go with them. Those are still made.
I’ll see if I can find the stuff in small enough pouches that I won’t have a huge amount to store at a time when I open them.
1 pound of calcium chloride will treat about 65,000 gallons of water at an initial 5 ppm concentration.
http://www.emergencyhomepreparation.org/viewtopic.php?f=25&t=97