I was thinking that before you spelled it out.
A check written to The Bearer can be passed around like cash, and upon proper confidence, traded for traditional cash. For proper confidence though, you probably either need ID or to actually know who is considered to accept the check. - Like a friend who trusts you.
So I am just restating this to clear it up in my and the readers' minds.
Cash is much like a bearer's bond but upon an FDR presumption that nobody will ever make the claim on it and redeem it. Therefore when somebody uses a big red stamp on the front of the bill, they are settling the agreement between the parties on both sides of the dead President. I actually suspect that if you were to pay a filing fee at the US District Court with such bills the clerk of court would be obliged to accept the canceled currency and not be able to tender/liver it to the bank for value. Upon doing so, the bank would not accept the bills for value and send them on to be destroyed by the Treasury.
It would be in fact that the USDC would be obligated to process your claim/case but upon your authority to make the claim, not upon a petition for the court to hear it. Like the post office labors to deliver the letter, but cannot re-use the canceled stamp.
P.S. In other words a bank is only your friend because they can verify the transfer of funds electronically or just tell you to wait a few days before you get your money, or both.