We bought these Lodge scrappers and they remove anything stuck to it.
https://www.lodgecastiron.com/product/pan-scrapers?sku=SCRAP...
Hot water and this kind of brush is all you need to clean cast iron:
https://www.lodgecastiron.com/product/scrub-brush?sku=SCRBRS...
https://www.restaurantsupply.com/tablecraft-254-stainless-st...
It’ll likely outlive me.