You know how parents will jokingly offer to loan out their children to childless couples as an effective form of birth control? I would be willing to offer similar services with my husband to unmarried couples. I will happily turn him over to you for the month and you can get a taste of what it's like to be married. Someone else can make all his meals only to have him whine and turn up his nose (and sometimes throw your food in the trash), someone else can clean up after him (dishes, laundry, and good luck introducing him to a trashcan), you also get to experience trying to sleep becuase you have to work in the morning while he is running around the house until 2 or 3 AM with lights on, AND you'll get the added bonus of dealing with his financial trainwrecks (and maybe not get to pay rent that month because he screwed up-- but promises it will never happen again! :) yay.)
It really seems like it would be a win-win. Unmarried couple gets to make an informed decision about what marriage is really like and if they want to go through with it after all-- and I get break from, well, all the lovliness listed above. I think this could be a very effective system.