Exploding rosaries? That might count as desecration. Also hows he going to fit the explosives into a bunch of small beads?
For a clearer description of technology: Imagine fallout. Replace mutants with demons, take away vaults and the astounding ability for technology to still work after being derelict for generations and that there is always stuff lying around even after centuries of scavengers picking over the rubble.
OOC will be up soon.