I've never in my life heard of that happening. I also volunteered to clean in the washrooms but we always had mirrors available.
We had bathroom lineups too...but that's because they took half of the available women's washrooms and made them either mother's rooms, or father's rooms (because god knows a father has never seen an exposed boobie breastfeeding an infant before...). So what usually happened was the lower level washroom had the aged and infirm winding halfway around the convention centre so that mothers and fathers (most of whom were 19 years old) could sit and chat with their friends. (yes, it peeved me)
Actually, thinking about it, I don't think I was comfortable for one assembly. It was a series of lineups...lineups to get in, lineups to get food (when there was food), lineups for the bathroom (which, if you were a good Christian you spent half your lunch in so you could be back and attentive when the program started), lineups to get in and out of the parking lot.
No wonder I always felt completely exhausted by the end. Bleh.
One funny story, was a year I was sitting with a friend and her hubby and baby. He'd brought his portable radio/tape player so he could tape some of the talks (with the baby they missed stuff). Right at the start of the afternoon program, the button got bumped and it BLASTED out hard rock from a local station. It echoed everywhere and I think it was the longest 30 seconds of the poor guy's life as he tried to get it stopped. Thinking back, it was pretty funny. ;)