I’ve literally done this.

Found a vial in a camp chair while buying doses at a three day rave. Thought it was an empty, put it in my pocket and rediscovered it on the dance floor a couple hours later. It wasn’t empty; it was one of those larger mint drop bottles and it was around 3/4 full, so well over a hundred hits. By the end of the weekend, i was literally just sipping off the vial.

Relevant video.