Do not throw away the desiccant bags that are coming with your new filament.
Just dry them thoroughly in a filament dryer and place them in a sealed bag along with filaments that you just dried.
If you use a dryer like the SUNLU S2, you just need to print a desiccant bag holder to dry simultaneously up to 18 bags.
Reusing is better that recycling, after all. 
Very raw video showing what I mean:
That’s great. The only thing missing is a link to the “silica bag holder”.
Link below:
Just a note that the Clariant pack shown below is not silica but rather clay based.
Thank you! Corrected the original post.
I noticed that as well, but the idea is pretty neat. I wonder how long it would take to restore silica bead packs in one of my Creality Space Pis. I can do in a microwave in about three minutes. 
Interesting. Please share your experience with drying desiccant using a microwave.
How long the drying time for a given quantity. Is it safe?
After seeing the print for that silica cage is around 9 hours, I may stick with the microwave. I buy the Wisedry brand of silica gel desiccant in 20 and 50g packets and in bulk. Thier instructions say 10-20 minutes per 500g (1.1lb) of pellets. It varies due to the microwave. With an 1100-Watt microwave, I’d use the lower number in a heat proof bowl. The indicator beads turn back to orange when dry. They turn dark green when saturated with moisture.
You can also use an oven at 350*F for 1.5 hours for the same 500g. I would use those numbers for an electric oven. NG or LP ovens produce a lot of water vapor during combustion so I wouldn’t even use those.
Note: I don’t get any compensation from the Amazon link. It’s there for information only.
Amazing! Thanks for sharing!