I bought a bunch of silica sachets off Ebay for a few dollars to experiment with, and so I tried adding 3 or 4 to a pill bottle with a couple of nugs. When I checked them a few hours later they were very crispy. And the herb vapes very well like this. (You 'recharge' the desiccant by baking it at a low heat for an hour). So yeah, a good way to dry your herb without having to heat it, and better for flavour. I'm thinking though, with my limited grasp of the chemistry, that dehydrating the herb like this is decrboxylating it, so if you're cooking unvaped weed, this could be a great alternative step to pre-baking.