I've been contemplating doing this ever since I saw the post of another blogger who did it. What to do if life gives you snow rather than lemons? Dye your yarn with it!
KnitPicks Bare Superwash DK Wool and some dye, a dedicated plastic tub, some metal racks, and (out of frame) a plastic bucket and white vinegar. First step: soak the yarn in a vinegar solution.
This was, as I recall, 1/2 cup vinegar per gallon of water for half an hour. Then the hanks were carefully hauled out and gently squeezed to be wet but not drippy.