Putting them in the fridge will put them in a state where they practically sleep and dont move. I usually keep mine for a few days in the fridge, then take them out and wait a few minutes to come back to life, then feed them a little, then put them back in the fridge, and repeat
When you say feed them a little did you mean the worms or your frogs? Because I keep my waxworms in the container they came in and I thought they could live for weeks in that same container without the need of gutloading.