Here’s the one thing you should never, ever use in hotel rooms

Hotels are hit or miss when it comes to cleanliness. Often times they look clean, but when you curl up into bed, you find a pair of dirty dude underwear under the covers.

Okay, that only happened to me once. But once was enough for me to always check under the covers before settling into a room.

An ABC News investigation has revealed another reason why you may want to check out a certain hotel situation before diving in. According to an investigation done at 15 hotels from Kansas City to Cincinnati to Baltimore, you should consider not using the water glasses in the hotel rooms.

11 out of 15 of the hotels failed to take dirty glasses out of the room to clean and sanitize them before putting them back in the room for the next guest.

Gross, right? It gets worse.

One housekeeper at the Millennium Hotel in Cincinnati was caught “cleaning” dirty glasses and a coffee pot in the sink with a bottle of Lysol mildew remover. Not only is that not sanitary, it’s poisonous.

Another housekeeper at a Kansas City Holiday Inn wiped her hands with the same towel she used to dry the dirty glasses.

And at the Embassy Suites in Phoenix, the investigation found that instead of replacing dirty glasses with clean ones, housekeepers instead just rinsed and dried them with a rag. Undercover cameras caught staff using the unsanitary cleaning procedure more than once.

So yeah, you should probably grab a bottle of water from the vending machine, or bring your own reusable bottle, and avoid using hotel water cups altogether. Safety first.