It’s simple. Do a little checking, and find as many people in your local area who suffer from Obsessive Compulsive Disorder (OCD) as you possibly can. Contact each person and tell them you are starting a group sharing session at your house for all those who suffer from OCD. Make it clear that anyone is invited to attend. People who have OCD will jump at the chance, especially if they think it will cure them.
Once they all arrive, just throw a big party, and let the people just hang around and shoot the breeze. It’s a sure bet that at least three of them will want to take the time to clean your house for you.