https://www.youtube.com/watch?v=6tHInlFfMcM
copy of the video description text:
Over the years, I've collected a lot of silica gel packages and regularly put them into my stuff, hoping that they will keep it dry. These tests showed me that there is more than silica gel in the typical desiccant packages and that if you don't properly dry them, they can even ruin your filament. Let's compare four different methods to keep your loose desiccant and your silica packages dry!
Chapters
00:00 Introduction
01:19 What's inside a desiccant bag?
01:54 Sponsor
03:19 Clay desiccant
04:57 Indicating desiccant
06:53 The problem with desiccant
10:26 Get rid of your desiccant bags?
11:06 Drying desiccant
14:38 Drying in a microwave
16:40 How much energy does it use?
19:34 Drying the bags in a microwave
21:48 Do you damage your desiccant in the microwave?
23:18 Summary
I'm surprised Stephan did not mention that bentonite clay is commonly used for cat litter.
China. That's where you can still get the Cobalt indicator and subsequently on Amazon, Aliexpress or ebay.
The upside is the fantastic color change, which is why some still prefer it and why it is probably still being made.
In Europe there is an alternative blue indicator that is cobalt-free, but it is more of a blue to brown/very dark red colour change, so not great either especially after a few drying cycles.