When times are tough (as they are now), it's tempting to consider any job interview opportunity as a victory -- not to mention a chance to practice your interview skills. One might also engage in wishful thinking, hoping (and expecting) that the interview itself will result in a magical transformation leading you (the job seeker) to actually want this very job that you only hours before had disdained.
Don't give in to either tendency. Don't waste your time (or the prospective employer's) chasing options that don't appeal to you. Life is too short. Focus your energies on looking for what you want. You'll do far better in an interview for a position you truly want than in one you have to force yourself to go on. Trust me on this point, as I speak from experience!