what's it worth?

We are lucky enough to have a good sized room in our basement that the kids use as a playroom. Actually what seems to happen is that the playroom spills over into the rest of the rooms in the basement, because the girls apparently regard the entire bottom floor as their zone. I wouldn't really have any problem with that, except that they never clean up after themselves. Slowly but surely (and sometimes not so slowly) the entire basement is transformed into a something resembling a home that has just barely survived some natural disaster like an earthquake or a tornado. Now I know that although I'm not down there actually making the mess, I still have to share the blame for it with my girls. Number one - I don't remember to enforce a clean up at the end of the day/play period a lot of the time. Number two - I encourage my kids to just go and play without my participation being necessary. Isn't that the whole point of having a big basement for the kids to play in? So play they do, and play hard. They are very into making stuff out of something else, so there is always a lot of cutting, gluing, painting, colouring etc going on, as well as a lot of fort building which necessitates dismantling all of the furniture and draping of sheets and blankets. And I think that's great. Except for that moment when I venture down at the end of the day to make sure the door is locked or get something from the freezer, and I enter the wreckage of that days activities. Because I know that I have let it go too far, and now when I ask them to clean up, they will take one look at what they've done, and be totally overwhelmed by the task at hand, and much wailing and protesting and dividing up of who actually messed up what will ensue.
So. I spent the weekend telling them to clean up, or there would be no play dates for any of them for a month. I thought that would be pretty good incentive to get them moving, as they love having friends over and vice versa. No dice. By Sunday, I threw in a monetary bribe, offering a dollar to anyone who cleaned up, providing the whole area was cleaned, not just what that particular person deemed "their" share of the mess. They lollygagged around all weekend, procrastinating until Monday rolled around and the mess had only deepened. I couldn't believe they wouldn't even do it for the money. So after school Monday I announced that until the basement was cleaned up, there would be no play dates for a month, no allowance of any kind, and no TV for a full week, which would include all of the coming weekend. Talk about pulling out the big guns.I went upstairs and let them work that one out. I don't think my kids watch a huge amount of TV, some in the evening sometimes, but usually very little during the week. But apparently that was the deal breaker. After a just a few minutes of frantic discussion, up they came to let me know they were ready to clean. I handed out garbage bags and helped them break the job up into separate tasks - one person in charge of toys, one for books, one for craft items and so on, and then I set up my ipod on the portable stereo for them and cranked it up and left them to it. And they cleaned. By the end of the evening it was done, and although it needs some tweaking, it looks about a million times better. Now I have to keep up my end and be the daily clean up enforcer so we don't have to go through this all again next week....