When you refund a mattress they just surface clean it
yuck. I doubt that. It’s manual work and far more expensive than a machine.
but getting them dry would be a challenge
seriously? I mean, there is a chance no such service exists in your town. Bad luck then. But there is close to zero chance it doesn’t exist in your country.
What do you think hospitals do? (Or good hotels, as mentioned). Source: Worked in an elderly home that used such a service regularly.
Here’s an image of such a mattress washing machine.
They work.
https://www.zischka-matratzen.de/.cm4all/mediadb/IMG_5804.JPG
I’d like to see the bedbug that survives this. As mentioned elsewhere, this is used by (hopefully) every hospital, elderly home or hotel for worse stuff than bedbugs.
The mattresses leave this thing in a pristine state.