cleaning a toilet help needed!

Ddaddy said
BTW, Coke is a very weak phosphoric acid solution and isn’t going to do much on heavy build-up.

https://www.amazon.com/CLR-Calcium-Remover-Biodegradable-Bottle/dp/B07HLW1HNK?tag=fabo03-20

I thought exactly the same thing, and was pleasantly surprised.
Much nicer for the environment .