Eucayptus and Lavender oils are great for things like this!
They have anti bacterial, anti fungal and anti septic properties. You only need a few drops straight in your toilet bowl and scrub as per usual.
You can also put them in an old spray and wipe bottle and use them to slean the seat, etc.

Oregano is also about 100 times more powerful than bleach. You boil it in a pit and then skim the water into a bottle and use as per spray and wipe. Safe to use on everything but stronger than bleach! Ace! lol That can get exxy though - but if you grow your own oregano it works very well.

Bicarb soda and vinegar is great to. Mix them together and they will fiz and bubble. The act of creating the oxygen is a highly powerful cleaning agent - great for shower grouts especially too, just use an old toothbrush.

HTH!