I was a bed wetter until I was 12 yrs old. It was very traumatic to have to go to school and know that there was a faint pee odor on my skin. Each night I went to bed fearful that I would 'fail' by morning. It was very frustrating and I felt powerless.
All of the gimmicks my mother tried were just adding insult to injury.
Eventually my mother took me to see a chiropracter. The Doctor said that my lower back was a little out, the muscles were a bit tight which would put pressure on the nerves. The signal from my bladder wasn't getting through at night when I was sound asleep. (I also was a heavy sleeper, I always woke up groggy and tired)
After the first session, I went home that night and woke up the next morning dry. It was the first time I had ever remebered waking up dry. It was complete shock.
I went for two more appointments and had no problems since.
Whether it was psycho-somatic or actually a real cure, it worked and it changed my life.
Before you unintentionally punish your daughter and disrupt her sleep with this device, try an alterior option, such as accu-pressure, chiropractic's, homeopathy....something that might help identify WHY she isn't waking in the night....I assure you it isn't because she enjoys waking up each night, FREEZING, lying in a puddle of her own piss.
It's a lot of laundry but never punish her, just put a plastic cover over the mattress, support her emotionally and help her to find power over the situation and her body.
PS: If she is open to it, put a diaper on her at night. Explain that it is NOT a baby thing, that even adults use them sometimes when their bodies aren't cooperating....that it is just a pre-caustionary measure to help her, her sheets and her blankets to stay dry and that it is ONLY for nighttime.
It may help to alleviate her embarrassment and frustration about waking up drenched and smelling like pee in the morning. Waking up in a warm dry bed may re-inforce getting up to use the restroom in the night and may eventually lead to waking up dry completely on her own.
I'd take her to a chiropractor first and see if you make progress there.