some chams will eat it from a bowl, most will not. its always worth a shot to try that first.
but the way i did it was to trick the cham at first. i was able to hand feed all my chams, so i got to the point where i could just pinch my fingers together and they would want to fire.
but i always had a small piece of veggie then the cricket on top of the veg. dangle the crick and get the cham interested. then at the last second change the angle of the two items so they think they are firing at the crick but you moved the veg there instead>>>>