A food dehydrator or the purpose built Sunlu would work great for this purpose, but in my opinion there are easier procedural ways that don't require additional appliances.
I just keep my spools in a large sealing storage tub with an oven safe tray of loose silica desiccant beads at the bottom. Every few weeks the tray of desiccant gets put through a heat cycle in the oven (about 150-75 for 10-15 minutes) and goes right back in the bin. You really only have to fight the moisture that gets absorbed by the spool while on the printer before going back in the tub, and the moisture within the air exchange every time the tub is opened.
Keeps my spools nice and dry without much fuss.