If there are thousands of bots watching the 66 address, which I think there are, they will all watch the mempool as well and keep increasing the fee against each other.  Maybe the answer is to send the transaction first with the entire amount as the fee minus 1 sat to your address and hope whichever miner that finds it will return it to you.  This way no one can increase the fee any higher and your timestamp is first.  Would that work?