Ever since we, as a species, mastered the art of indoor plumbing, the humble lavatory has morphed from a place people go to do the unmentionable to a quiet refuge from the daily grind. No longer do we have to squat precariously over a hole in the floor or pay a visit to the perpetually cold outhouse, the glory of the porcelain bowl supports us during our best and worst times.

This is why it can be upsetting and slightly guilt-inducing when you are greeted with the sight of a colourfully stained toilet bowl upon lifting the seat. With this guide and a little bit of effort, you won’t have to be faced with such a sight and you won’t have to listen to the shrieks of horror and disgust when guests use your toilet.