I wouldn't feed them, even if you could get your chameleon to eat em. Unless you killed them yourself (and why would you do that...) you will have no idea how long they have been dead and how much decomposition has occured. The whole idea makes me cringe, right up there with canned crickets and silkworms.
Serious problems can occur when chameleons ingest bacteria which are probably covering a cricket that has died. Also the cause of death might be a reason in itself of why you wouldn't want to feed it. I would say don't do it just to be on the safe side.