If these are adults you can withhold food for a couple days then offer him a super or silkie. Are you cup feeding? I would sometimes get a super to climb the screen and she would go after it, but they fall a lot so you have to stay right there.
You can also try something that is flying, such as houseflies or moths around lights at night. For the flies be sure to order from a breeder (skipio, grubco, kammerflage) as they feed on decaying matter in nature and the breeders feed them on a clean diet. As for moths at lights most of what you find are OK, but if you're unsure post a pic. Of course if you live in the north you wonlt be seeing any moths for a while
Other than that you may just have to stick with the crickets - or roaches. Have you tried roaches?
Yes, butterworms have an odd smell, don't they? A quick sniff is not unpleasant but more than a moment and it's a bit much. These are caterpillars of a moth form Chile and they are serious wood borers! They should ONLY be cup or hand fed for the reason you mention. You will see them next as the moth and if a male and female find each other you may have lots of baby butters!
These are a great calcium and moisture source, but also fatty and should only be a treat anyway. You can offer one in your hand or in a cup first meal of the day when hungry and s/he may take it.