But will that work if the slave is caught in a loop or some such?

I'm aiming for a complete reset with no decision from the slave.
could do.........
1)
'
restarting:
pause 1000 ............... wait a second or 2 to reset all
@ RESET
'
or 2)................
if all slaves are on same 5 or 3 volt supply, then use a small NC (normally closed) relay to turn off power for few seconds to restart all slaves