Calciworms are Pheonix worms. I have fed Pheonix as a staple feeder for my smaller Chams for about a month ( i had a large amount i got from a expo). Didn't have any issues at all. I didn't even have to dust since they carry a fair amount of calcium ( hence the name). I wouldn't worry too much about them, i think they are a great feeder.
But varity is key, so offer different feeders options to your Chams.