Have a devious plan of pouring dish soap down the hallway.
Seriously, why would you want to do something like that?
I want to see if people are going to slip and fall.
You shouldn't try to intentionally cause harm to people. Also your wasting resources and you could find a lot of other better things to do with your time.
I'm not sure I agree with you, I think this would be a very funny prank.
Regardless if it would be a very funny prank it's not worth the risk of causing harm to someone. If you want to make people laugh laugh you should do something that doesn't involve causing harm to others.