Similar to "Steal this Book" and its advice on marijuana:

> There are two other ways that we know work to increase the potency of grass you grow or buy. One consists of digging a hole and burying a stash of grass wrapped in a plastic bag. A few months in the ground will produce a mouldy grass that is far fuckin' out. A quick method is to get a hunk of dry ice, put it in a metal container or box with a tight lid (taping the lid airtight helps), and sprinkling the grass on top. Allow it to sit tightly covered for about three days until all the dry ice evaporates.