Hi all! I found a fog machine at a garage sale and bought it. I looked it up when I got home, and it is from Party City. So I went to buy the "fog juice" today, and saw there was cleaning fluid as well. Is this something I need to buy? The salesman said it's a good idea if you use it a lot. Since I bought it used, I'm thinking I should get it. But I wanted your opinions. Thanks!