I feed dubias to my cresties.
Some of my cresties that are older and have been on CGD only their whole lives are a bit pickier, but one of my younger girls hunts 'em down like the predator jumping down from on high with mouth wide open.
In addition to feeding CGD by hand: I like to use a chopstick to offer it. Just dip the chopstick and get enough goop on it. The smaller food vehicle is easier to maneuver the food to the gecko's face, and doesn't spook 'em as easily.