Yes, but there are better options for green manures, without the risk of being thought of as a habourer of vermin.
Apart from the usual options in the garden centre, this year I am using brown mustard seed, because of its reported efficiacy in sorting wireworm. Commercially its sown at 2kg/acre. I obtained 200gm packs from my friendly ethnic grocer for 99p each. Also its good for pickling. (They also had spirit vinegar, 5%, at £3.39 per 5 litres.)
Other useful, cheap options are wheat, lupinseed, sunflowers , all from the pet shop. If you have an area of "waste" ground, why not 'grow and mow' any bulky green plant. The choice would depend on what you can get cheaply.Chickory, peas, beans etc. A use for suspect or surplus seed. The secret is to not let it seed!