A-Zoom, in my experience and as GL9CK reports, are not great for repeated dry firing. I use them mostly for function checks and teaching load/unload in NRA Basic Pistol Classes.
Traditions brand snap caps - clear plastic with a visible spring and a red base - do not work for function checks because they do not conform to cartridge dimensions - but last much longer for dry firing. They still get dented over time and need to be replaced.
For .22 rimfire, check the local hardware store for yellow screw anchors, size 4-6. They will work as snap caps for .22 but need to be rotated as they develop dents from the firing pin.