I have looked at those rounds that are effectively non powder/primer reloads, with plastic. I like the weight idea, but haven't done it for different reasons. I have considered using empty casings/fired, and trying to epoxy weights in them, but plan on always having one of the typical red snap caps on top.
Besides that, I have and often use a laserlyte in my pistol for dryfire.
LEO relative recommended using some spent casings, randomly for bad round practice, and for dryfire practice.