I have tried several barriers to keep the flies from getting stuck in the honey, and the most effective was the plastic grid. The grid slanted in a 2 ounce serving up keeps most (but not all) from the "honey pit." I use the dry food mostly, and shake the feeders in Yens Blend which has powdered crystallized honey in it.
For moisture I do NOT like water, as it invariably spills, and makes a fly soup. I use cricket cubes from the pet store.
You can see the Cup-o-Flies to see how the flies are housed and how the grid lays in the portion cup, and the grid is under General Supplies.
Although it takes longer, if you really want honey in your mantis, use a bamboo skewer and wipe it on the forarms, they will clean it off. I add Yens Blend to it so they get bee pollen at the same time.
CHEERS!!!
NIck Barta
Mantisplace.com