Recently I discovered that clove essential oil is one of the best natural mould killers going around. It's primary ingredient, eugenol kills over 60 strains of bacteria, 15 strains of fungi and several viruses. Armed with this knowledge, I decided to make some "mould killer" which I spray around when some spots appear in the shower, when someone has been sick in the toilet (or on the floor) and even in the kitchen sink. Key is to spray it on and leave it for approx 20+ minutes.
In a 500ml spray bottle you only need 10 drops of clove essential oil to 500ml of water. Easy eh! Give the bottle a little shake before spraying.
Note: this mould killer will kill the bugs HOWEVER, elbow grease is the only thing that is going to get rid of any stains, just keep that in mind. I hate to promote this but I have been known to kill the bugs with my spray and then use a bleach product to remove the mould stain. Not recommended if you want to go all al-ah-natural but good if things have got a bit out of hand and elbow grease hasn't worked.
I looooooove the smell of cloves so I spray this mixture around just for the fun of it as a bit of an air freshener. No harm in doing so, it's all natural.