It would be interesting to see if something like that could be created. Maybe for when people purchase large item contracts like a house without escrow insurance.
The ledger will always be there as long as transactions are being made, but context would be hidden. There are also many advantages from a trading point of view such as the avoidance of making ripples in the market (changing price, thus changing average entry or exit point), and can offer more sophisticated trading order types such as iceberg orders which would make the receiver or sender much less obvious according to the blockchain.
Interesting point on purchasing items, can you expand/clarify on what you mean?