Any way to block-ban entire genre of music?

I like to mix it up by listening to the "my recommendations" and "my neighborhood" radios. But on occasion I get CHRISTIAN ROCK. I am not a religious person, so this music really offends/annoys me.

Is there any way I could ban an entire artist or genre of music?

Of course I can always ban each song as it starts playing, but what if I'm not fast enough and Last.fm learns to think I like christian rock? Yikes, scary thought.

Thanks so much! It seems to be mostly one band that pops up in the recommendations, so should be easy.