It is a big misconception that the placebo effect must be ineffective — there wouldn't be an effect at all if that was the case. I hear it's sometimes even effective when you're told you're taking a placebo.
I think the placebo effect still working even if the person is told it is a placebo is a factor of whether or not you consider placebo to be "bad" or "ineffective". To me it just suggests a difference in the actual mechanism of how the placebo is effective. I'm curious to know if there are ways to increase the effectiveness of placebo by having a strong/pleasant smell or taste associated with it or some other sensory effect that is immediately noticeable.