It's hardly a secret that the plane toilet isn't very clean, though it may come as a surprise to learn that some flight attendants rarely use them.

"I only use the lavatories on the airplane if I need to wash my hands or if I absolutely have to go to the bathroom," an anonymous cabin-crew member said. "If it's a short flight and I can leave the plane, I'm definitely waiting until I can use the bathroom in the airport."

Flight attendant Kelly Goodnuff agrees and thinks that "it's disgusting" when passengers go to the bathroom without their shoes on.

That's why it helps when passengers make an effort to clean up after themselves in the bathroom. It certainly doesn't go unnoticed by the cabin crew. Former flight attendant Sudewo said that staff "greatly appreciate" fliers who ensure that toilet paper has been thrown way, the toilet has flushed, and water — and even phlegm — from the sink and floor has been cleaned up.