A small confined space and lack of airflow can leave a plane toilet smelling less than fresh.
To combat bad smells, flight attendants have a surprisingly simple trick.
The Sun reports crew from Norwegian Airlines revealed that pouring a strong cup of black coffee down the toilet helps to neutralise the odour.
"The reason coffee is so effective is that it both neutralises the bacteria and also brings with it a very familiar new smell,” the publication explains.
Another trick involves leaving coffee bags on the ground to offset the smell.