As far as i know mate they're great for absorbing moisture, so i wouldn't go throwing them in a jar of perfectly cured homegrown. But if its just some you've bought and its a little wet it may be worth a shot, i'd play it safe and go with the old mull up and air out. What the silica packs are great for though, are storing with your seeds in the fridge I've got a beauty going from a seed that was fridge'd for two to three years!