re: Anyone ever filed a Affidavit of Small Succession to get money out of a bank account?

Can't vouch for it, but this site has a downloadable affidavit form for a Louisiana small succession for a person who died intestate (no will). LINK

I can imagine 19 ways to disaster doing this without a competent lawyer, so good luck.

When you go to the notary, sign/execute multiple originals, more than you think you will ever need.

Print a copy of Louisiana Code of Civil Procedure article 3434 to show any bank that balks. It says:

A multiple original of the affidavit authorized by Article 3432 or 3432.1, shall be full and sufficient authority for the payment or delivery of any money or property of the deceased described in the affidavit to the heirs or legatees of the deceased and the surviving spouse in community, if any, in the percentages listed therein, by any federally insured depository institution, financial institution, trust company, warehouseman, or other depositary, or by any person having such property in his possession or under his control. Similarly, a multiple original of an affidavit satisfying the requirements of this Article shall be full and sufficient authority for the transfer to the heirs or legatees of the deceased, and surviving spouse in community, if any, or to their assigns, of any stock or registered bonds in the name of the deceased and described in the affidavit, by any domestic or foreign corporation.