Don't feed crickets corn meal of any kind. There was an article posted in the Bearded Dragon forum not to long ago reporting that crickets fed cornmeal produce toxins that are harmful to reptiles though the toxins themselves don't harm the crickets.
The FLukers gel stuff isn't good either, it's probably what is killing your crickets since it tends to swell up inside of them. It can also harm your reptiles as well.
To feed your crickets, feed them mixed greens, Rep-cal's gutload (the dry stuff) or even bearded dragon pellets. For moisture, use sliced oranges, pototos or carrots (change every day to avoid mildew buildup). Also, clean out any dead crickets you find as this will greatly reduce the smell. ALso, make sure you don't store the crickets where it gets too hot or too cold (I beleive 70-80F is a good temp range for crickets).