If it's in a code review, it's been committed to some branch in source control. If it makes it past the code review, it's now a part of your product.
If people want to use this approach as a training exercise (as mtlynch suggested in a sibling post), that's one thing, but that's not what OP suggested, and what OP suggested seems like pretty risky advice.
If the deliberate mistake makes it past code review then you just remove it before merging anyway. A workflow where you are not allowed to fix anything in your own PRs before merging them unless they are explicitly requested by a reviewer would be very strange.
If people want to use this approach as a training exercise (as mtlynch suggested in a sibling post), that's one thing, but that's not what OP suggested, and what OP suggested seems like pretty risky advice.