/diy/ - Do It Yourself

I have an unusual predicament. I work as maintenance for an apartment complex. All one building, apartments open to an interior hallway with elevators in the center of the building and two stairwells at either end. You cant get into the building without a key fob or someone buzzing you in.

For some damn reason we have residents who let the drug addict homeless into the building, which leads to these meth heads sleeping, shitting, pissing, and everything else in the stairwells for me to have to clean.

What are some ways I could booby trap the stairwells so they leave? I have a plan to sprinkle powdered lye on the carpet on each of the landings so when they try to lay down to sleep they get a chemical burn, but I'm open to suggestions.

Sorry to say but it cant be anything that damages the property or kills the person. I dont want to have to make a second thread asking how to deal with a corpse.