As long as you've got a good aim, try standing up. Sitting on a bucket used by everyone else can spread germs, and squatting can feel awkward, you could overbalance and knock the whole "urinal" over, and could lead to joint problems if you do it too much!
Incidentally, you don't have to use a P-mate to pee standing up! Search around WikiAnswers, there are many ways to aim and do it just like boys with just your fingers. Learn how to and spread the word!
http://neptune729.deviantart.com/art/Peeing-Standing-Up-for-girls-112663453 Is my guide to how girls can pee standing up. Try it out!
The situation that you describe is a very difficult one. If all else fails, use a bucket, which you can empty out and clean later. It is, of course, more socially acceptable to simply wait until the bathroom is available, but as you say, sometimes you can't hold it. If you do not have a bucket handy, sitting will help. There just seems to be something about the position that helps reduce the urge.
If you discover a water leak in the ceiling below your bathroom, you should immediately turn off the water supply to the bathroom, place a bucket under the leak to catch dripping water, and contact a plumber to fix the leak as soon as possible. It is important to address the issue promptly to prevent further damage to your home.
Just tell your parents you want to be able to pretend you are camping in your room. Or, that you don't want to turn on lights when you need to walk to the bathroom at night.
anything, but water is the healthiest
Because those are the healthiest vegetables
It depends on how clean the bucket is :)
the healthiest answer i should say is to pray. http://www.bestjobsmagazine.com/
go to the bathroom
You pull the utters of a female cow above a bucket and the milk should go into the bucket.
The bathroom floor should be of a slip-resistant material surface, whether it be tile, stone, vinyl, or carpeting.
Never pass up a bathroom
For aesthetic and practical use, bathroom mirrors should be placed at waist level. The bathroom mirrors should offer a one meter clearance from the ground.