Is it possible and safe to freeze rechargeable NiMH batteries to revive them?
NiMH batteries can form dendrites internally that short out the battery. This is probably what is causing the symptoms you see. The usual way to deal with this is to discharge a big enough capacitor into the battery to blow out the dendrites.

However, if your batteries have been shorted for a significant time, which appears to be the case, they have been irreversibly damaged. These batteries shouldn't be discharged below about 900 or 800&nbsp;mV. In your case they've been at 0&nbsp;V for some time. Even if you could revive them, their capacity would be very low.

Ditch them and move on.