I think, in general, the organic methods remain the same for most of the crops within a species...they are not crop specific....any non-chemical methods for cereal crop would hold good for finger millet, too.
One of the most "out there" techniques of weed control is the introduction of ducks and geese. Apparently some types of these poultry can really go through a lot of vegetation, and provide other benefits such as free manure. Its all pretty funny but check it out