I actually agree with that notion as well, but it could be said that it's always going to be a worry of ours, all things considering that aeternam literally has a voice in her head. And it's hardly likely that stabbing ourselves will help with this one. Personally speaking, I think it prudent to just go along with this mind control, as the black icky wants us to survive long enough to be a challenge, and our partners subconsciously doing it probably isn't going to end in our demise.
So again, stabbing ourselves probably isn't the right way to go about this.