Passengers on an Air Canada flight demonstrated why you should always clean your seats as they wipe off layers of dirt from their headrest.

Filmed on August 20, the passengers flying from Victoria International to Toronto Pearson Airport decided to wipe down their row's headrests.

They found that the aisle seat had the least amount of dirt whereas the window seat had the most.

The filmer told Newsflare: "We did not talk to the crew. We have put out a complaint to Air Canada today (September 3), but they haven’t responded yet."

An air passenger wipes down her seat only to find the wipe caked in black dirt. Three wipes come away black on one headrest. Additionally, it's seen that wipes used on seats closest to the aisle come away cleanest, pointing to lazy work done by Air Canada staff.

Why you MUST clean your airline seats— Air Canada fail!