They might get skin cancer
This isn't directed to the OP, but for a general audience.
Just for the record, UV sterilization would undoubtably not kill anything on the interior of the brush, which is where most moisture resides and pathogens can hide. Most pathogens cannot survive outside the body for greater than 3 days, so that alone inactivates most organisms. Furthermore, soap and water, or borax, will kill or remove just about anything.
Barbicide is used because it can kill microorganisms in 30 minutes, as opposed to waiting for days and then washing.
Autoclaving, besides being complete overkill and totally ruining the brush, is necessary for surgical instruments and research supplies. In the former to prevent infection, and in the latter to prevent contamination. Even a tiny amount of non-pathogenic bacteria can ruin research samples, so it is imperative that nothing survives which could grow in culture media.
The reality is that people go overboard when it comes to cleaning used shaving supplies. People eat out at restaurants and use utensils that have been in other people's mouths without thinking about it. Granted, they get run through a dishwasher, but the point is still the same. If the idea of using a used brush grosses you out, and the "tried and true" techniques sound dubious to you, I would suggest just buying new going forward.
I doubt any damage was done. That thing's made so your wife can stick her fingers in there to cure nail polish, right? If it won't damage her skin, I can't see how it could damage your brush.
Please don't do this freezing therapy. Ice expands and damages things. A good soak in a sanitizing solution will be all that is needed. I probably would consider a mild "boric acid solution soak" after researching the possibilities or contacting a reputable brush maker for suggestions.Wet the brush. Freeze the brush. Ice crystals will kill the microorganisms. If you're afraid of virii, use dilute hydrogen peroxide for 10 minutes. 5-10%.
That UV thing is a toy. UV should emit heat.
I use Marvicide on occasion as it says on the label safe for brushes. I prepare it per instructions and do the ten minute soak right to the base of the knot and not submerged. It will leave the tips of a brush temporarily blue, but goes away quickly with a hand lather or two. Makes me feel better as I work on the hematology field. It has never effected any brush I have done it to in a negative manner whatsoever. I don't consider you purchasing some of it a break in your sabbatical by the way.
Just saw this and have to disagree. Shaving related purchases is a shaving related purchase.