Themed Wash-In
That certainly sounds like fun. How about the theme be more along the lines of "I wore all white-clothing to a party last night and spilt everything on me. Which washer and which detergent will work best?" (Certainly NOT the PlanetArk stuff I was rattling on about in my thread here in Super).
I also like the idea of a Dish-In. I think to make it effective with 27 full-size (or thereabouts) machines, you'd need around 324 items minimum... So that probably equates more around 1000 dishes - and with a group of 50 people, each person would basically have to bring a dinner set for 20 each (and they'd all have to be dirty). Can you imagine being pulled over by the Police, "Yes Officer, I was just taking these to my friends house because he has 27 dishwashers he wants to test. There's another 49 of us headed there too. Do us a favour and don't tell the EPA, all-right?"
Or would it be more like this?
{Slowly waves hand about}"These are not the dirty plates you are looking for. That'll be all... Move along!"
{Officer}"Those aren't the dirty dishes we are looking for. That'll be all sir... Move along please!"