Rather, our "certificate of debt" was nailed to the cross. This was the idiomatic use for cheirographon, handwritting. This was discovered from a great many papyrii found in the Egyptian city Oxyrhynchus. Paul uses this in Philemon, "If he owes you anything I'll repay it, see, I've written in my own hand."Under the New Covenant the law has been abolished, Ephesians 2:15. Jesus nailed it to his cross, Colossians 2:14.
The practice was you would write your acknowledgement of indebtedness, and give it to your creditor. When you paid, they would write on it "tetelestai", and give it back to you. "It is finished".
I heartily agree with the balance of your post.
Much love!