I would suggest to use your own piss and do what you need to do to make your piss clean, dullution, supplements so you dont come up dillute. I have never used any kind of device to substitute urin. I used to sub(i put the pee in a pill bottle and stuck it in my sock, I wouldn't suggest doing this, I was EXtremly lucky, only ladys worked there and they did not check the temp.