I keep them in the fridge to keep them dormant and pull them from the container as needed. Do they eat in the container while in the fridge?? When do I feed them (the worms) ???
I don't keep my supers in the fridge at all, they die... I don't feed my waxies either. The only things that I keep in the fridge that I actually feed is my mealworms. I take them out 1-2 times a week for the day, and feed them then. Then I put them back in the fridge.
For superworms, I personally keep them in a bran and rice infant cereal mix and add in collard greens, mustard green, dandelion greens, sweet potato, squash.. what ever i am using to gut load crickets with. They eat it up. Just be sure that if the dry bedding (bran/cereal) that they are in gets damp AT ALL that you change it to remove the risk of mold or bacteria buildup.
Here are some sites with feeding instructions for waxworms...
http://www.chameleonsdish.com/insects/waxworms.htm
"blend baby cereal, honey, hot water and a teaspoon of cooking glycerin in a food processor until the baby food is clumpy yet somewhat moist. Bee pollen can be added for extra health benefits".