Hmmm...It WOULD give you a place to lay the magazine down...the toilet tank would be a great desk to do the crossword...we might be on to something here...
In that situation (If in fact it did happen), the right thing to do would've been to look that woman straight in the eye and go, "What? Doesn't anyone KNOCK anymore?! While you're here, you got a pencil? I wanna finish the crossword. Oh, and maybe some Lysol?" If you're gonna go, go with gusto.