I put bleach in the toilet and now it’s ugly brown look in the base of it
I use bleach and let it soak on stain for half an hout then brush with a heavy duty sponge.
Pour a bottle of Diet Coke in it, let sit for a few minutes and flush.
Lysol Lime & Rust Remover Toilet Bowl Cleaner and Mr. Clean Magic Eraser worked better for me than bleach.
Denture cleaner tablets (the fizzy kind).