How do I remove the yellow urine stains from my toilet bowl please
Drink more water
Apparently you want Cylitbangs bleach & hygiene ☺
I would try white vinegar since the stain is likely to be held in a calcium deposit unless the plastic has been cleaned with abrasion.
A cream cleaner such as Jif.
.... Cif
I use descaler first and if that doesn't remove everything, Domestos for the rest, rinsing well with fresh water afterwards.