I have one and it doesn't hit too bad. I have never personally used one in public but I noticed a guy using one at an IronMaiden concert. I only noticed it because of how often you have to light it, and he smoked a few of the tiny bowls. He was in the seat right in front of me, but if you didn't know these already existed I doubt I would have noticed.

Could somebody post a picture of their dugout? I'm really not sure what it looks like.