Hi there!
We don’t use them all the time and it really depends on how far a cham is traveling and the temps at all the point along the way. They are handy when it is hot because they will extend the life of an ice pack!
We always free range our silks. Put a few on the branches and usually the chams come running. Keep trying and try what you said. Offer the silks and not crickets/BSFL for a day. See if he eats them.
We have always raised silks for our own collection but we are now trying to be consistent about having enough to sell to others!! And the feeders are great! My son makes the feeders for extra money! He does a nice little business! Thank you for the support!