Yes.

Would it be possible to reap without the OP knowing they've been reaped? Have posts go invisible to everyone else while the 'brigged' member is still able to view them. Maybe even allow them to edit and reply to threads all while no one else can see them. (Ideally keeping them blissfully ignorant).

References:
• Clive Thompson on the Taming of Comment Trolls : Wired
  • See second half of the article on making troll posts invisible
• Anger Management for Online Trolls : Wired
• Redesigned YouTube Takes Aim at Boob Tube, Trolls : Wired

But, l.r gets the upvotes for presenting an interesting idea with some background info to support it; but not because I favor brigging punitive action without notice. Frankly, I don't see much benefit in keeping a malefactor "happy" or "contented" while being punished. But YMMV (and possibly MM will V some other day).

OTOH, will brigging someone and then allowing that individual to participate in the CB have a deleterious effect; say, a case where the brig-ee makes using the CB unpleasant with complaints, maledictions and just plain BS?

Caveats aside, I think jdp's idea is worth implementing.

Well, in terms of overall/long-term harm/benefit to the community, the ranting which people do in the CB is of no consequence.

...UNLESS the ranting paints the CB (and, by unreasonable but quite human extension, PM itself) as a fiefdom of nutcases; as a place where the unpleasantries lead a visitor to write off the site as 'too testy to bother with.'

As I said before, I like the idea; I hope we implement it, but -- even more -- hope we carefully consider the pluses and minuses. (And, of course, my {dark} notions of possible downsides may be unrealistic.)

For sure. (But now I gotta go catch a bus.)