Just turn down the heat when it starts boiling and you won’t have any mess at all. Boiling pretty much anything without using a lid is just plain dumb and a waste of energy. The only exception being if the point of boiling is to reduce water content.
I’m seriously baffled by the amount of people in this thread having issues with something as simple as boiling plain rice. What the hell, its not fucking rocket science. Do you have trouble boiling pasta too!?