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.
Some (usually cheaper) indicating desiccants use cobalt-based dies which are fairly toxic, but unless you are using them to keep food dry it's not a huge issue. Having them break into powder in the microwave probably isn't great though, I'd avoid breathing any of it in
The orange indicating gel is less toxic, but it's still not good for you. Don't dry any indicating silica gel in the same oven you use for food. The clear silica gel is non toxic, but breathing the dust can cause silicosis.
The powder can settle on your food just like if can settle on your lungs.
I'd recommend not using the same microwave you use for food to dry died desiccant.