Some of the multivitamin with D3 supplements will look like there’s nothing sticking to the feeders, but it is. If you feel like it’s not sticking well enough to roaches, try crickets or silkworms (as already suggested). I like to hand feed silkies to help promote building and keeping trust. It also is a good way to keep them from sticking together in a silkie ball. For some reason the back of my hand is less frightening than the palm, so I put a single silkworm on my hand and extend it out near to where my cham is and can see it while I look away and wait. If the silkie falls off your hand, put it back on and keep trying. It takes a lot of patience at first. If your cham is seeming too afraid to get that near to you, try putting the silkie in a shallow bowl that you can hold out. I have even gone so far as to close the enclosure door as much as possible and turn my body so I’m not even facing my cham. Before you know it, you’ll have your cham come running when he sees you, expecting food and not caring much if it’s on your hand or in a feeding station.