That design is asking a lot from wood. You could do it with metal, but wood needs bracing.

Have you considered adding metal L brackets?

I've successfully dried filament with these Eva Dry packs: https://a.co/d/eBVuUEE

I'm sure a dehydrator would be faster and drier, but I've used these to take a roll from printing poorly to printing acceptably in a few days. Just make sure it's freshly recharged and you put them together in a small airtight container.