Perlite will dry out fairly quickly on it's own because it is a volcanic glass and is used to make for better air space and drainage.Adding about 40-50% vermiculite,which does absorb moisture,should help.Also putting a plastic baggie over the containers top will increase the humidity,just let it air out every few days.
If the cuttings show some green,underneath where the bark is scratched,they are probably still vital. Brady