I have used them to feed my flytraps in very early spring, or young plants I have propagated that are indoors under lights for the winter (I dig around and find the tiniest mealworms that are about 1/4 inch long or less). Also for my nepenthes. In the summer, it's flies, ants, moths, etc., - and wasps for my monster sized flytraps!.
They work well - not too much rot. But you do have to keep an eye on them, since sometimes they squeeze their way out.
Did you know you can raise them easily? We have a large chameleon and we supplement his diet with them. I use a plastic box (about the size of a shoebox) with a snap on lid with holes in it. Fill it about 1/3 up with wheat bran and put a potato in there for moisture. The mealworms turn into pupae (great for VFTs too), then beetles, which lay eggs and the cycle continues.