I enjoy the goofy side of teaching. Entertainment value can go a long way in getting children to buy what you're selling. This one though, I mean, I've done dumb stuff before, but this is in the top five.
Ok, so kids lining up at the door. Not ideal. Step 1, make a restriction zone near the door.
Works well. Start jokingly referring to it as lava for a few days. Step 2, actually spell it out as such.
Immediately challenge them to jump the lava to gain entry. Step 3, line of teenagers at the door waiting to jump/avoid the lava.
I'll pass the mic to Kate here.