My toilet has been neglected. It isn't at the biohazard stage, but there is a lot of limescale. With the water round here and my intermittent use of the brush, it builds up really quickly. Bleach hasn't had much effect in the past as while I am confident it kills germs, it just bounces off the limescale. Today I poured down a load of white vinegar - perhaps as much as half a pint, left it for a little while and the limescale almost wiped off - no scrubbing! I may never use bleach again, just a spray of disinfectant and then vinegar. Or I could use the orange vinegar that Bless uses in a spray bottle - so much cheaper.
As an aside, apparently you can make your own bleach with salt water and a car battery. Personally I think that is an invitation to disaster in my accident prone kitchen, and inexpensive bleach is extremely inexpensive. I'm sticking with the vinegar for now.