Just putting spools in a dry environment will dry them some but it’s a very slow process. It takes heat to be able to dry filament on any practical time frame.
Just to cover the bases, new filament fresh from the shipping bag may not be dry (and frequently isn’t). It’s a coin flip on if it will print properly.
A user here (forgot who) started seeing moisture effects so put a spool in a dry box and it did improve their prints. Thing was they had just started seeing effects so there wasn’t a lot of extra moisture involved. At the edges of what prints properly moisture-wise you might be able to get away with it depending on your own ambient environment. Or you might not.
For better drying you need heat. For best drying you need low humidity too.
Not saying your issues are water. Only saying especially with filaments like PETG that love water a little too much, heat is generally needed for drying.