The weird trick flight attendants use to keep the plane toilet smelling clean.

Tightly packed bodies, stale air and questionable food aside, there is one grave travel experience more universal than the rest: the foul stench of the communal toilet.

If I’ve caused you any triggered flashbacks, I’m honestly sorry, but hey, that means you know exactly what I’m talking about, right?

But according to Norweigan Airlines, there’s a simple and effective way flight attendants work to eliminate said putrid smells, and it’s all thanks to coffee.

Flight attendants, we're stealing this trick from you. Image: iStock

Speaking to Traveller earlier this month, the flight attendants say they clean the loos every 20 minutes and add that nothing fights off high-flying bowel stench quite like a pot of coffee being poured down the toilet.

This is because caffeine not only neutralises bacteria, but also the unforgettable smell.

And if you're thinking all of this sounds somewhat familiar, it's because it is.

Every time you walk into a department store and find yourself near a perfume counter, it's likely you'll see glass upon glass of coffee beans.

And, according to Dr. Alan Hirsch, a researcher from the Smell and Taste Research Center in Chicago, the reason for said beans is because your sense of smell is seriously smart. Whenever a new smell is introduced, it will make itself very, very well known and stay with you.

Listen: Another awkward thing about travelling? Having to 'mime' at the pharmacy. (Post continues after audio.)

But by introducing a scent neutraliser like coffee beans, you can wipe the slate clean and move onto smelling something else.

So in other words, if you go to the aeroplane's toilet before said coffee cleanse, the smell of others is really going to not only present itself but stick with you.

If you go after, though, you should be okay.

What are your travel hacks? Let us know in the comments section below.