entomology - How long does it take for a cricket to die at subzero temperatures?

I am on a number of reptile groups and I often hear freezing recommended as a humane way to get rid of surplus feeder insects.

However, they can also revive if you don't leave them in there long enough.

If I had a bag of crickets and put them in the freezer, how long would it take for them to die in this way?