I'm a little late on this, but...

Spencer's Gifts sells rolls of toilet paper that you can't use. Its un-rip-able (if that's even a word)

Also, super glue her tooth brush bristles. Depending on what kind of locks you guys have, you can lock her in the place with a quarter wedged the right way (don't worry, you can open the door from the outside... its a tricky stunt and you need a certain kind of deadbolt lock, etc)

Shaving cream bombs. Take a manila envelope and fill it with that shitty old white shaving cream. Make sure you duct tape 3 sides of it. Slide the 4th side under a closed door. Jump down on the envelope... BOOM! Shaving cream everywhere. Its guaranteed to take at least 2 hours to clean up