Don’t keep flushing bleach down the drain, use natural ingredients to clean your toilets, it will have just the same effect and you can rest assured you are not polluting the environment.
Mix together one cup (250g) of borax with either lemon juice or distilled white vinegar to make a fairly thick paste.Use this to clean the bowl and in all those hard to get places and leave it to do its work for about 15 minutes. Use a scouring sponge to remove any stubborn marks and then simply flush the toilet to reveal a fresh clean bowl.
Andrews' Family Cookery & Household Management 