Since we can break down weapons, accessories, etc, down into essences, it makes since to be able to do the same thing to green steel. You would receive back all of your materials, small, medium and large, but not the shards of power or energy cells.
In addition it would require a reasonable amount of money, thirty thousand plat for tier I, sixty for tier II, and one hundred twenty for tier III, to deconstruct a green steel item, due to the danger of doing so.
Also, to further make it difficult, players would be required to trade with their plat a "Shavarath Rune of Dismantling" which would be available in the DDO store for 100-300 points, or a rare drop from Devil's of Shavarath quests.
Thoughts?