Well, I would logically shout it from the bathroom.
"Hey dude, can you do me a favor and bring me some toilet paper, there\'s none in here."
They\'ll bring it to the door, drop it off, you open it, grab it, and proceed to wipe. If your shit stinks, that\'s life. Whatever. I guess I\'m just a person who doesn\'t care if someone has to do their required business in my house or not and doesn\'t feel embarrassed in pointing out that I use toilet paper to wipe my ass and would like some if there\'s none in the bathroom to do the wiping with.