Well, those ever “mostly harmless” blobs of fur and noise known as “Marsh Mallows” have been used as an *cough* interrogation device by my sister.
(She says she got the idea from me, somehow, but I don’t see how.)
She simply placed the horrific creature on the poor subjects head, and let the fun ensue.
It trilled, the subject thrashed and screamed.
And then it began to settle, or ooze though nobody is certain, down over the cranial casing of the subject.
Eventually his pleas were little more than somewhat muffled cries of “Whargaarrggle” coupled with trills and other odd noises.
We are in the process of inspecting the Marsh Mallow for signs of having taken control of the body.
You’d probably get better market acceptance if you advertised them as a hair replacement therapy.