Using a toilet seat cover can be tricky business. I've never docked a space shuttle or defused a bomb, but I imagine these pursuits are about as difficult as placing a sanitary sheet on the john.

Simply extracting one of these covers from its dispenser is a confounding task, and the instructions (“1. Pull Up. 2. Pull Down”) don't help. You're just as likely to grab a whole clump of them in one go or tear a thin strip of tissue and nothing more. When it comes time to place it on the seat, there’s no ready-made hole in the logical place but rather a perforated semi-oval. This leaves a droopy tongue that hangs listlessly, its purpose unclear.

Google Patents

A 1919 patent for Jacob P. Young’s “Sanitary Stool-Seat Cover” looks to be one of the earliest versions of this device, and it features a whole slew of flaps. One goes above the upturned lid, another hangs over and outside the front of the toilet, and a third “constitutes a protecting guard for the male.” This invention is only somewhat similar to the ones used today, not least because it’s implied that the cover is meant to be reused.

Cornelius J. Dykstra’s 1922 patent for a disposable toilet seat cover will look more familiar. The invention includes a “flap adapted to extend down into the toiletbowl and to partially rest upon the water there-in, so that when the toilet is flushed, the engagement of the flap with the water will cause the entire cover to be passed out with the flushing.” Unfortunately, he doesn’t mention at which end we are supposed to place said flap.

Subsequent patents for more complicated toilet seat covers mention a front-facing flap, like this one that has a “water-soluble oxidizing agent … [that] provides a microbiocidal shield between the toilet seat and the buttocks when perspiration (not shown) from the buttocks contacts both the water-soluble oxidizing agent particles and the water-soluble enediol compound particles allude to a front-facing flap.” Terrific.

Also, multiple YouTube instructional videos shot in bathrooms of varying degrees of cleanliness say that one should place the flap in the front of the toilet bowl:

The question of where you are supposed to put the flap seems to be settled, but the larger issue of whether or not these covers are even necessary remains. FiveThirtyEight ran a breakdown on their effectiveness, and the results aren’t encouraging for Team Seat Cover. Public health officials stress that it’s almost impossible for an STI to be transmitted via contact with a toilet seat. And as Dr. William Schaffner, a professor of preventive medicine at the Vanderbilt University Medical Center, told HuffPo, “Toilet seats are not a vehicle for the transmission of any infectious agents—you won’t catch anything.”

We naturally perceive toilets to be gross, so if you need the peace of mind that a seat cover provides, use one. That is, if you can figure out how.