A few more weeks didn't show any more drying of PETG, even with a dry cold front pushing up pumping activity. Suspect the grey color doesn't absorb as much heat as TPU & it's slower to absorb or release water. The equilibrium might be a point where the pump still turns on every day rather than a point where the pump never turns on. There could be a newly formed leak.
All the filament has been dried during the driest winter in Calif* history. In past winters, there would be many cloudy days or even rainy days where the pump wouldn't turn on & leakage might cause the filament to reabsorb water. How well it works in a normal winter or whether it gets dry enough in normal humidity is still unknown. 1 scenario has the dehydrator permanently storing filament during normal weather. Another scenario has the filament transferred to ziploc bags after the 1st dry cold front.
There was an attempt to make a desiccant pack out of some calcium chloride to save money. The leading idea was a paper towel & some scotch. It's definitely not as durable as the $7 Bezos item.
TBH, the lion kingdom has serious doubts if those $7 packs really work. How does the fabric really change color? Does the fabric color accurately reflect the water content? Does the air really get through the fabric? How durable are they really? They certainly have the packaging & marketing to appear intended for a certain use. If calcium chloride works, the drytote should be dunked in some water to test it.