Smoke Or Screen?

As all of the most sucessful silhouettes have been done using sunset and the sun as the light source behind the subject, but I can't always use the sunset as it means I would have to travel every evening to somewhere good enough to shoot the silhouettes. Luckily the sun has been out at the moment so I have been doing quite alot of sunset silhouettes. So I have been looking at indoor techniques and figuring out my own way of producing silhouettes, using flash behind the subject. The one problem with this, is that if you use flash on it's own, it has nothing to bounce off and doesn't work too well, or will only work with smaller objects. I will be posting my results of this soon. I then realised I needed something for the light to bounce off, so I tried using paper to spread it a bit more, and that did work better but still not as well, and I couldn't get the paper to stay up. I was thinking how to make a good silhouette, and with a big background to shoot with, such as a big sheet or something, but with the flash to bounce off enough to light a full body. I was thinking about it and talked to my mate about it. I then realised smoke would make the flash bounce off widely and probably would work really well. I then tried this with incense sticks, and some small objects and it worked really well. I then thought about how I could produce a smoke cloud big enough to get a full body silhouette, without starting a big fire or doing anything illegal. I looked around and bought some smoke pellets, that are used for testing chimneys. I had a test play with these, but the wind ruined it a bit, so I'm going to have another play with this soon and try and get my final images out of it, as I think if I practice enough I can get a really good shot with them. And have some ideas in my head of how to do this.