If that is the idea, it does not work for reasons:
- further spend attempts will not be broadcasted by a node after one of the attempts is included into the mempool
- people will figure soon that miner have advantage grabbing the outputs and stop trying.
Therefore the attack, if that is the purpose, is pretty lame.
I don't think that was the purpose of the attack. However, there are thousands of those dust transactions, all of them the same size, so the client can just select inputs that haven't already been spent. Even if it double spends, it is still spam that clogs the network, which might be the idea here. Also, why would miners grab the outputs? In order to spend all of those transaction, they need to create a transaction that is larger than 1 Mb and it wouldn't be worth that much. It would be more effective for them to mine other transactions that have higher fees and they can both earn more money and confirm and clear more of the backlog.
I tried to claim those BTC along with another address that was used for spamming but the transaction required a 2.4 BTC fee.