Sometimes, used mattresses can be handy. Such as when you accidentally punch a hole in the bottom of a river, and need a way to plug it.

https://en.m.wikipedia.org/wiki/Chicago_flood

Wow, thanks for linking that. Super fascinating. I just watched https://www.youtube.com/watch?v=Y-qD6h6wlU0 to learn more about the Chicago flood. Hard to believe!

I'd love to know if this is actually true. Can't these companies clean the mattresses and resell them, or at least donate them? Is destruction the only safe way?

A little more about the return process: https://www.nytimes.com/2016/09/17/your-money/buying-a-mattr...

And some anecdata: When I wanted to return an online mattress, I had the option of showing a receipt for giving it to a charity, or having the mattress company pick it up. None of the local charities I looked into took even slightly used mattresses. So the mattress company "pick up" was from a junk disposal company, and they just took the mattress to the waste transfer station on its way to the landfill.

My girlfriend used to work for a reasonably well known mattress company. Apparently returned mattresses there were given to charity for use in homeless shelters and such.