Interesting observation which more or less confirms my own findings.
I've been using my humidipak for over a year now and am still on the original set of packs. I keep a damp DIY wet sponge "humidifier" in the small storage compartment in the case and let the humidipack either absorb or release moisture as it needs to. Checking the moisture content in the sponge every few weeks has been working really well for me so far- and at over a year, it's been working great. And I keep my guitar stored next to a heater!
For those with rock hard humidipaks, try the cheapo damp sponge in the case and allow the humidipak to do its thing
