A few days ago I answered a call light to find pt. standing at the sink thoroughly rinsing out his mouth over and over.
"Sorry, but that mouthwash the doc brought me has gone bad I think!" he kept saying in between swishes. so I looked at the label and sure enough, it was tearless shampoo!
It turns out that while the doctor was examining him (an attending even!) the Pt. mentioned how he really wanted some mouthwash, and the doctor figured he would "help out the nurses" and grab it for the pt, since the room was right next to the supply closet. Of course he grabbed the wrong bottle, and the pt started swigging without looking at the label after the doc left. (No harm done, shampoo was non-toxic and pt spit it out as soon as it hit his tongue). Luckily the pt. had a great sense of humor and laughed when I told him what had happened.
The best part though was seeing the doc's eyes when another nurse who had seen him leave the supply room stopped him in the hallway to thank him for "being a team player and grabbing that shampoo!"