Ya i agree with pigglett,,,,as long as you gutload them,,,and they do eat a lot!!!! Then you could just go straight to stomach and dust whatever the next tender morsel is!!!
Horns and silks have a much less schewed cal: phos ratio than crickets so IMO unless you are mostly feeding those and no other dusted prey I wouldn't bother dusting them with calcium.
I do not supplement anything I consider a "treat". Which includes both of those. If you can get them to take greens a day or so before that would be a better choice.