It's very nice. I use the shower curtains to completely seal myself in. Use water to seal the curtains to the wall. If it's too hot or hard to breath, just open up the curtains a bit to let in air.

It's better if you got a shower with a door and use duct tape to completely seal it shut. But it can also be a bitch. I dropped my ONLY lighter in the tub lol! Just make sure you got an extra lighter. I guess a candle would be better.
Another thing- soap/shampoo mixed with steam will help get rid of the smell which is also great.