I'm not comfortable creating sentient lifeforms. Unless we're dead certain we know what we're doing, the results could easily be evil or an pile of organs in continuous pain. We could probably science our way out of the latter with animal trials, but the former could be hard to detect. And evil is a distinct possibility, given how our powerset works and the possibility that all Feathers needs is an appropriate vessel to incarnate into the world. Which is also a reason that I'm a little leery of magicking up a body. A scienced-up body is a little less risky, but real science is hard and time-consuming.
It sounds like you're not going to be comfortable with dewitching as a whole, then, because human experimentation, creating/tampering with sentient/artificial lifeforms, and fucking around with people's very immortal
souls is implicitly part of the process. We
can't be
totally certain with what we're doing, either, because what we want to do is to the best of our knowledge
completely unprecedented, and we have only the most nebulous grasp of the theory: The people who got the closest had to work with trial-and-error experimentation, and a dozen evil clones is what they wound up with.
Fortunately, as I said, creating a human body is the
easiest part, and as far as dewitching itself goes, a non-Euclidean mass of pure psychotic agony is our
starting point, so it's not like we can really hurt a Witch more than it's already suffering. We
should be working on low-risk experiments to suss out theory and procedure before Riona gets here, though, because we only know that she's a "soul expert" (whatever
that means), and if she knew how to dewitch people quickly or easily, Kyuubey would have arranged a tragic accident for her a
while ago.