I know that you have more than enough answers, but I'd like to share my own experience with this kind of interview.

I'm basically an IT guy. I have worked and studied all my life with programming and stuff. I had received a interview request in a large Callcenter that mostly just hire people for telemarketing.
To see if I would fit in, I went to the interview.
I don't want to sound rude, but when I entered in there, I just knew that it would not be the environment that I would like to work. It would be a entire day interview, so, I let the recruiter present the company and the roles that we would fit.
Seeing that I would not have any kind of chance to work in programming or IT, I politely went to one of the recruiters and asked if there was any way of getting a job that I would fit in. As they said no, I said that this job offer would not be of my interest, and then I leaved.

Does this sound extremely rude from my part? Yes, I think it does.
Would I lost an entire day in there knowing that I would not like to get the job? Yes, I would.
Do I regret it? Nope.

My point is, I saved both mine and the recruiters time and efforts on leaving. I asked nicely and I would do it again. Just be nice with everyone and you will be good to go.

I know that you have more than enough answers, but I'd like to share my own experience with this kind of interview.

I'm basically an IT guy. I have worked and studied all my life with programming and stuff. I had received a interview request in a large Callcenter that mostly just hire people for telemarketing.
To see if I would fit in, I went to the interview.
I don't want to sound rude, but when I entered in there, I just knew that it would not be the environment that I would like to work. It would be a entire day interview, so, I let the recruiter present the company and the roles that we would fit.
Seeing that I would not have any kind of chance to work in programming or IT, I politely went to one of the recruiters and asked if there was any way of getting a job that I would fit in. As they said no, I said that this job offer would not be of my interest, and then I left.

Does this sound extremely rude from my part? Yes, I think it does.
Would I have lost an entire day in there knowing that I would not like to get the job? Yes, I would.
Do I regret it? Nope.

My point is, I saved both mine and the recruiters time and efforts on leaving. I asked nicely and I would do it again. Just be nice with everyone and you will be good to go.