I have learned this technique, because many times while feeding my frogs a cricket would drown in the water before the frog could find it. (please dont drown the cricket on purpose)
How To Save A Cricket After It Drowns: (Works most of the time.)
1. The cricket should not have been in the water for more than 4 hours.
2. Take the cricket out of the water, gently dry it off with a napkin, and place it in a dry cage, with a paper towel or napkin lining the bottom.
3. Put some food in the cage.
4. Place the cage in a warm, dark place, for about 2 hours.
5. After 2 hours, check on the cricket, touch it, it should be walking around and alive.
6. You have now saved a crickets life, I usually kept mine for pets, since they earned the right to live.

